Implantable medical lead including voiding event sensor

ABSTRACT

An implantable medical lead includes at least one stimulation electrode and at least one sensor configured to generate an electrical signal that varies as a function of a parameter associated with a voiding event of a patient. In some embodiments, the sensor may be at least one of a microphone that captures sounds associated with voiding events, a pressure sensor, a flow sensor, a strain gauge, a physiological parameter sensing electrode or a temperature sensor. The electrical signal generated by the sensor may used to detect an occurrence of a voiding event. Thus, the lead may be coupled wirelessly or via a wired connection to a device that processes the electrical signal from the sensor, generates voiding information based on the electrical signal, and in some cases, records the voiding information for later retrieval and analysis.

TECHNICAL FIELD

The invention relates to medical devices and, more particularly, devicesfor the treatment or diagnosis of urinary or fecal incontinence.

BACKGROUND

Urinary incontinence, or an inability to control urinary function, is acommon problem afflicting people of all ages, genders, and races.Various muscles, nerves, organs and conduits within the urinary tractcooperate to collect, store and release urine. A variety of disordersmay compromise urinary tract performance and contribute to incontinence.Many of the disorders may be associated with aging, injury or illness.

In some cases, urinary incontinence can be attributed to impropersphincter function, either in the internal urinary sphincter or externalurinary sphincter. For example, aging can often result in weakenedsphincter muscles, which causes incontinence. Some patients also maysuffer from nerve disorders that prevent proper triggering and operationof the bladder or sphincter muscles. Nerves running though the pelvicfloor stimulate contractility in the sphincter. A breakdown incommunication between the nervous system and the urinary sphincter canresult in urinary incontinence.

Monitoring urinary incontinence aids a clinician in diagnosing theprecise condition of the patient. For example, a clinician may monitorparameters of voiding events, such as time of voiding events (voluntaryand involuntary), volume of leaked fluid for an event, number of voidingevents, and contents of urine, in order to diagnose the condition of thepatient. Accordingly, monitoring may include collecting urine samplesfrom the patient and/or maintaining a patient voiding diary in which thepatient logs voluntary voiding events, involuntary voiding events, i.e.,leakage, or other related problems. The patient may keep the voidingdiary on paper or in an electronic device. The clinician may review thesamples to determine the contents of the urine and may review the diaryto view the frequency and number of voiding events experienced by thepatient. In some cases, the clinician may tailor a therapy, such aselectrical stimulation, according to the diary and the contents of theurine samples.

SUMMARY

This disclosure describes methods and systems for maintaining anautomatic voiding diary. The device detects urinary or fecal voidingevents by processing a signal generated by a sensor and records voidinginformation for the detected voiding events. The voiding information iswirelessly transmitted to an external device, such as a patient orclinician programmer, that presents the voiding information to anauthorized user, such as a clinician. The voiding information obtainedover a series of voiding events forms an automated voiding diary that isuseful for diagnosing a condition of the patient and determining theefficacy of therapy delivered to treat urinary or fecal incontinence. Aclinician may also manually adjust therapy parameters based on thevoiding information. In some embodiments, the device may include therapyelements or communicate with a therapy delivery device to delivertherapy, e.g., electrical stimulation, drug therapy, or a combination ofboth, or automatically adjust therapy parameters based on the voidinginformation.

Maintaining an accurate voiding diary is often difficult for a patient.With some manually-maintained voiding diaries, the patient manuallytracks voiding event, such as by manually writing down the date and timeof the voiding event or providing an input via an electronic device.With manual voiding diaries, there may be a risk that the patient mayneglect or forget to record all the necessary information. For example,a patient may neglect or forget to record the time at which the voidingevent occurred or identify the voiding event as a voluntary orinvoluntary event. A manual diary can also be inaccurate because entriesby the patient are subjective and may be influenced by embarrassment orother issues.

This disclosure describes various systems and methods that provide anautomatic voiding diary that records a patient's voiding events withoutthe need for significant patient interaction. In one embodiment, theautomatic voiding diary detects voiding events based on an electricalsignal generated by a microphone. The microphone may be a crystalmicrophone, condenser microphone, a ribbon microphone, or other type ofmicrophone. The microphone translates sounds associated with voidingevents into an electrical signal. The sounds may be internal sounds ofthe patient or external sounds. Internal sounds may be sounds generatedby the bladder, urinary tract, rectum, intestines, or other organs andtissue that produce noise indicative of a urinary or fecal voidingevent. External sounds may include sounds produced by the patient orenvironment during a voiding event, such as fluid being voided into atoilet, flushing of a toilet, fluid exiting an opening in the urethra ofthe patient, or other sound associated with voiding events.

Detecting voiding events based on the electrical signal generated by themicrophone may involve processing the signal by, for example, comparingor correlating the electrical signal with a voiding signature stored inmemory. The voiding signature includes a characteristic of an electricalsignal that is generated during an actual voiding event for a patient.In one embodiment, the voiding signature used to detect voiding eventsis an example signal generated by the microphone during an actualvoiding event. The voiding signature may be individualized to aparticular patient or may be applicable to more than one patient. Thisexample signal is referred to as a signal template. In this way, theautomatic voiding diary may utilize an initial training or calibrationmode to establish a voiding signature, i.e., capture a signal template,that can be used to detect a voiding signature in the signal generatedby the microphone.

The automatic voiding diary may be configured as an implantable medicaldevice (IMD) or an external device. When implemented as an IMD, themicrophone may be located on or within a housing of the IMD or on a leadcoupled to an IMD. In one example embodiment, the IMD may be configuredas an independent diagnostic device that wirelessly communicates with animplantable therapy delivery device, such as an implantableneurostimulator (INS) or implantable drug pump, and external programmersfor the implantable therapy delivery device. In another exampleembodiment, the automatic voiding diary may be configured as an IMD thatoperates as an automatic voiding diary and a therapy delivery device.

When implemented as an external device, the automatic voiding diary maybe implemented as part of a personal digital assistant (PDA), cellphone, watch, programmer for an INS or other implantable therapydelivery device, or other personal electronic device. Alternatively, theautomatic voiding diary may be implemented as a dedicated device thatthe patient may carry or attach to clothing. In any case, the automaticvoiding diary may be configured to communicate with a implantabletherapy delivery device and programmers for the implantable therapydelivery device.

In some embodiments, a device may include a feature for identifyingdetected voiding events as voluntary or involuntary events based on apatient defined action. The user friendly feature is useful formaintaining a substantially automatic voiding diary implanted in thepatient to identify an automatically detected voiding event based on apatient defined action. For example, the patient defined action mayinclude manually tapping the skin located proximate to the automaticvoiding diary. In this example, the automatic voiding diary includes anaccelerometer that generates an electrical signal based on one or morecharacteristics of the tapping, e.g., the number, frequency, andduration. The automatic voiding diary processes the accelerometer signaland records the appropriate identification information in memory.

In some embodiments, the lack of a patient defined action may be used toprovide additional information. For example, an automatically detectedvoiding event may be identified as a false positive when a patientdefined action is not received within a pre-determined period of timefollowing the detection of the event. Identifying voiding events basedon a patient defined action that is detected via an implanted medicaldevice may eliminate the need for the patient to carry a separateexternal programmer to enter identification information for detectedvoiding events. The identification information in the voiding diary maybe particularly useful to a clinician for determining the efficacy oftherapy and manually adjusting therapy parameters. In one embodiment, atherapy delivery device automatically adjust therapy parameters ordeliver therapy to prevent or reduce involuntary voiding events in thefuture in response to the automatic voiding diary receiving input, i.e.,a patient defined action, that identifies a voiding event as aninvoluntary event.

In another example embodiment, an implantable medical lead that carriesone or more sensors is coupled to the automatic voiding diary or, morespecifically, a device that includes the automatic voiding diary. Theelongated body of the medical lead extends between a proximal endcoupled to the automatic voiding diary device and a distal end thatcarries the one or more sensors. The automatic voiding diary deviceprocesses the signals generated by the sensors to detect voiding events.The sensors may be one or more microphones, pressure sensors, flowsensors, strain gauges, sensing electrodes, temperature sensors, or anyother type of sensor used for sensing a parameter associated withvoiding events.

The lead may be particularly advantageous in embodiments that use theautomatic voiding diary device in combination with a therapy deliverydevice. In such embodiments, the lead may be introduced to a targetsensing site in the same way as a therapy lead is introduced to a targettherapy site. In other words, although the target sensing andstimulation sites may be at different locations, the leads can beintroduced through a single incision. For example, a target therapy sitemay be proximate to a sacral nerve, such as the S3 sacral nerve.Typically, a therapy lead, i.e., a lead carrying stimulation electrodesor a fluid delivery device that delivers one or more drugs, isintroduced into the S3 sacral foramen to access the sacral nerve.Stimulation of the S3 sacral nerve may help treat urinary and fecalcontrol disorders. In this case, the sensing lead described in thisdisclosure is introduced through the same or a different foramen andpositioned or guided to the target sensing site. In this way, additionaltrauma to the patient attributable to the implantation of the sensinglead is avoided.

Further, some embodiments may utilize a combination lead. A combinationlead carries sensors for detecting voiding events proximate to itsdistal end and delivers therapy for urinary or fecal incontinence. Oneexample of a combination lead is a medical lead that includes one ormore stimulation electrodes. The stimulation electrodes may be locatedadjacent to the sensors proximate to the distal end of the lead,interspersed with the sensors at the distal end, for example, in analternating fashion, or otherwise positioned anywhere along the lengthof the lead. Another example of a combination lead in accordance withthe present invention is a fluid delivery device for delivering one ormore drugs that carries the sensors at the distal end.

A combination lead that may be particularly advantageous includesstimulation electrodes or openings for delivering drugs along a mediallylocated portion of the lead. In this case, the lead can be positioned sothat when it is fully inserted, the stimulation electrodes or openingsfor delivering drug therapy are positioned at the target stimulationsite, such as proximate to the S3 sacral nerve, and the sensors arepositioned at the target sensing site, such as proximate to a portion ofthe bladder, intestines, or rectum.

In one embodiment, the invention is directed toward an implantablemedical lead comprising a lead body, a sensor coupled to the lead body,wherein the sensor is configured to generate an electrical signal thatvaries as a function of a parameter associated with a voiding event of apatient, and a stimulation electrode coupled to the lead body.

In another embodiment, the invention is directed toward a systemcomprising a medical lead that comprises a lead body, a sensor coupledto the lead body, where the sensor is configured to generate anelectrical signal that varies as a function of a parameter associatedwith a voiding event of a patient, and a stimulation electrode coupledto the lead body. The system further comprises a voiding monitor thatreceives the electrical signal from the sensor and generates voidinginformation based on the electrical signal.

In another embodiment, the invention is directed toward a methodcomprising receiving a signal from a sensor carried by a medical leadimplanted in a patient, where the signal varies as a function of aparameter associated with a voiding event, the medical lead furthercomprising a stimulation electrode to deliver electrical stimulation tothe patient, and generating voiding information based on the one or moresensor signals.

In another embodiment, the invention is directed toward a methodcomprising implanting a medical lead in a patient, the medical leadcomprising a stimulation electrode and a sensor configured to generatean electrical signal that varies as a function of a parameter associatedwith a voiding event of a patient, and coupling the medical lead to avoiding monitor that receives the signal from the sensor and generatesvoiding information based on the electrical signal.

In various embodiments, the invention may provide one or moreadvantages. For example, the automatic voiding diary records voidingevents without the need for significant patient interaction and may beimplanted within the patient, incorporated as part of a personalelectronic device, or implemented as a wearable electronic device thatautomatically generates a voiding log. This may eliminate the need for apatient to keep a manual diary and, therefore, may provide a moreobjective and accurate log for review by a clinician and therapy basedon the log.

In addition, information from the automatic voiding diary may be used ina closed loop system implemented by the automatic voiding diary orassociated IMD to automatically adjust stimulation parameters based onthe measured parameters, detected voiding events or an identification ofvoiding events as controlled or involuntary. In this manner, theautomatic voiding diary may provide adjustment to the therapy inresponse to detecting an involuntary voiding event. Consequently, theautomatic voiding diary may, for example, control a stimulator thatstimulates a nerve or muscle of the patient to prevent the patient fromunintentionally voiding his or her bladder in response to detectingvoiding events.

In embodiments in which the automatic voiding diary recordsidentification data for voiding events based on a patient definedaction, the additional input may be useful for diagnosis of the patientand selection of a therapy for the patient.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a schematic diagram illustrating an embodiment of a systemincluding an implantable medical device (IMD) configured to operate asan automatic voiding diary and deliver therapy for treating urinaryincontinence.

FIG. 2 is a block diagram illustrating components of the IMD of FIG. 1.

FIG. 3 is a block diagram illustrating components of a programmerassociated with the IMD of FIG. 1.

FIG. 4 is a schematic diagram illustrating a system that includesseparate devices implanted within a patient, where the devices areconfigured to deliver therapy to treat urinary incontinence and operateas an automatic voiding diary.

FIG. 5 is a block diagram illustrating components of the automaticvoiding diary device in FIG. 4.

FIG. 6 is a schematic diagram illustrating a system including anembodiment of an external device configured to operate as an automaticvoiding diary.

FIG. 7 is a block diagram illustrating components of the external deviceof FIG. 6.

FIG. 8 is a conceptual diagram illustrating a system including anotherembodiment of an external device configured to operate as an automaticvoiding diary.

FIG. 9 is block diagram illustrating components of the example externaldevice in FIG. 8.

FIG. 10 is a flow diagram illustrating an example technique forautomatically detecting voiding events and recording voiding informationfor the detected voiding events.

FIG. 11 is a flow diagram illustrating an example technique forcalibrating an automatic voiding diary device in accordance with anembodiment of the invention.

FIG. 12 is a schematic diagram illustrating an example IMD that recordsvoiding information based on a patient defined action.

FIG. 13 is a schematic diagram illustrating various components of theexample IMD in FIG. 12.

FIG. 14 is a flow diagram an example technique for recording voidinginformation based on a patient defined action.

FIGS. 15A and 15B are schematic diagrams illustrating a system includingan IMD configured to operate as an automatic voiding diary and coupledto an implantable medical lead that carries one or more sensors fordetecting urinary and fecal voiding events, respectively.

FIG. 16 is a perspective view of an example medical lead that may beused for detecting voiding events and deliver therapy to a patient forurinary or fecal incontinence.

FIG. 17 is a block diagram illustrating various components of an IMD andthe implantable medical lead of FIG. 16.

FIG. 18 is a flow diagram illustrating an example technique forimplanting an implantable medical lead for detecting voiding events anddelivering therapy to a patient for urinary or fecal incontinence.

DETAILED DESCRIPTION

Urinary and fecal incontinence are conditions that affect the quality oflife and health of many people. Urinary incontinence is an inability tocontrol urinary function and is a common problem afflicting people ofall ages, genders, and races. Likewise, fecal incontinence is aninability to control bowel movements. A variety of disorders maycompromise performance of the urinary tract and anal sphincter and,thus, contribute to incontinence. Many of the disorders may beassociated with aging, injury, or illness.

Tracking voiding events may be important for diagnosing a patient'scondition, such as by determining the number of voluntary or involuntaryevents a patient has within a certain time range (e.g., a day or aweek), or for selecting an appropriate course of treatment, which may ormay not include stimulation therapy, for the patient to treat theincontinence. However, manually tracking voiding events, e.g., keeping awritten or electronic voiding diary, is often undesirable orinconvenient for the patient. Keeping the voiding diary takes time outof the patient's day and may be noticed by other people, causingembarrassment to the patient. In addition, manually tracking voidingevents may result in voiding information errors. For example, thepatient may inadvertently forget to record an event, fail to objectivelydescribe the event, or even purposefully keep false voiding informationin the diary. These problems with a voiding diary may undermine theability of the clinician to properly assess patient condition andprescribe an effective therapy.

Systems described herein include a device that is configured to operateas an automatic voiding diary for recording voiding events without theneed for significant patient interaction. The device is referredthroughout this disclosure as an automatic voiding diary and generallydescribed for recording urinary voiding events. However, it should beunderstood that the automatic voiding diary may also be configured torecord fecal voiding events.

FIG. 1 is a schematic diagram illustrating a system 2 that includes animplantable medical device (IMD) 12 configured to automatically recordurinary voiding events and deliver therapy to patient 10 for urinaryincontinence. IMD 12 may also be configured to provide an alert forpatient 10 to seek medical follow-up in response to, for example,detecting that the therapy delivered is inadequate or the efficacy oftherapy is degrading. The alert may be provided via patient programmer16 or other patient monitoring system (not shown). As shown in FIG. 1,system 2 includes IMD 12 and patient and clinician programmers 16 and18, respectively, in wireless communication with IMD 12. IMD 12 deliverstherapy to patient 10 for urinary incontinence via therapy element 15and includes automatic voiding diary 14. In particular, automaticvoiding diary 14 automatically records voiding events without the needfor significant patient interaction. The voiding diary may be used todetermine the efficacy of the therapy, e.g., by determining the numberof controlled voiding events and involuntary voiding events duringtherapy delivery or by determining the therapy program being implementedby IMD 12 at the time the involuntary voiding events occurred. Inaddition, the voiding diary 14 may be used to manually or automaticallyadjust therapy parameters with which IMD 12 delivers therapy to patient10 or trigger therapy delivery in response to detecting a voiding event.

In general, automatic voiding diary 14 detects urinary voiding events byreceiving one or more electrical signals from a sensor that vary as afunction of a parameter associated with a voiding event and processesthe electrical signals generated by the one or more sensors to generatevoiding information. The voiding information may be recorded for thedetected urinary voiding events. The parameter associated with a voidingevent (i.e., a voiding parameter) may include, for example, pelvic nerveactivity, the content of leaked fluid, amount of leaked fluid,temperature of leaked fluid, pH of the leaked fluid, bladder volume,bladder pressure, sphincter pressure, bladder impedance, volume ofvoided fluid or a sound associated with the voiding event. The one ormore sensors may generate the signal may include, for example, one ormore microphones, pressure sensors, flow sensors, strain gauges, sensingelectrodes, temperature sensors, any other type of sensor used forgenerating a signal indicative of a parameter associated with voidingevents, or any combination thereof. In the case of measuring bladderimpedance, the impedance may be measured between at least two electrodespositioned at different locations on the bladder.

The voiding information may be wirelessly transmitted to one or both ofpatient and clinician programmers 16 and 18 or another computing device.Patient and clinician programmers 16 and 18 may present the voidinginformation to an authorized user, e.g., a patient and clinician,respectively, as a voiding diary or log. As described in further detailin this disclosure, a patient may review the voiding diary to manuallyadjust therapy parameters within pre-determined settings and/or confirmthe voiding information. A clinician may review the voiding informationfor diagnostic purposes, i.e., monitor the condition of the patient, toevaluate the efficacy of IMD 12 or of particular therapy programsincluding one or more therapy parameters implemented by IMD, or tomanually adjust therapy parameters. Patient and clinician programmers 16and 18 may also, in response to receiving the voiding information,automatically adjust one or more therapy parameters based on thereceived voiding information.

In FIG. 1, automatic voiding diary 14 includes a microphone (not shown)that translates sounds associated with a urinary voiding event into anelectrical signal. The microphone may be a crystal microphone, condensermicrophone, a ribbon microphone, or other type of microphone suitablefor implantation within patient 10. The microphone may be positioned onor within the housing of IMD 12 or carried on therapy element 15, whichmay be, e.g., a medical lead or a fluid delivery catheter. Inparticular, the microphone in automatic voiding diary 14 may translateinternal or external sounds into an electrical signal. Internal soundsmay be sounds internal to patient 10, such as sounds produced by bladder20, urinary tract 22, or other organs and tissue (not shown) thatproduce a sound associated with a urinary voiding event. External soundsmay be sounds produced by patient 10 or the environment during a voidingevent. An external sound, for example, may be a sound produced by urinebeing voided into a toilet, a toilet flushing, urine exiting urinarytract 22, urine being voided into an undergarment, or other soundsassociated with a urinary voiding event.

Examples of systems and methods that include a microphone as a sensor togenerate an electrical signal that varies as a function of a soundassociated with a voiding event is described in commonly-assigned U.S.patent application Ser. No. 11/755,559 by Martin T. Gerber et al.,entitled, “AUTOMATIC VOIDING DIARY,” and filed on the same date as thepresent disclosure, the entire content of which is incorporated hereinby reference.

In embodiments in which automatic voiding diary 14 is used for recordingfecal voiding events, internal sounds may include sounds produced by therectum (not shown), intestines (not shown), such as sounds produced byfecal matter moving through the bowel during a voiding event, or otherorgans and tissue (not shown) that produce sounds associated with afecal voiding event. External sounds include sounds produced by patient10 or the environment during a fecal voiding event, such as feces beingvoided into a toilet, a toilet flushing, feces exiting the rectum, fecesbeing voided into an undergarment, or other sounds associated with afecal voiding event.

IMD 12 may typically be subcutaneously implanted the body of patient 10,e.g., in the lower back, lower abdomen, or buttocks of patient 10. Whenimplanted at one of these locations, a microphone positioned on orwithin the housing of IMD 12 may be capable of reliably picking upinternal and/or external sounds associated with voiding events.Alternatively, the microphone may be carried on therapy element 15coupled to IMD 12. In this case, therapy element 15 and, moreparticularly, the microphone carried by therapy element 15 is positionedat a target sensing site that may enable the microphone to pick upinternal or external sounds associated with voiding events. However, insome embodiments, IMD 12 may be implanted at the target sensing site,which may be proximate to a portion of bladder 20, urinary tract 22, orother organs or tissue that produce sounds associated with voidingevents. In those embodiments, a microphone carried on or within thehousing of IMD 12 may be placed at the target sensing site without theneed for therapy element 15 or another member coupling the microphone toIMD 12. In another example embodiment, the microphone may be a wirelessmicrophone configured to be implanted within patient 10 and communicatewith IMD 12 or an external device, such as patient and clinicianprogrammers 16 and 18.

In any case, the location at which the microphone is positioned mayaffect the quality of the signal produced by the microphone. For thisreason, it may be desirable to position IMD 12, and in the case of animplanted microphone carried on therapy element 15 coupled to IMD 12,implant the therapy element 15 such that the microphone is proximate tothe source of the sound that is to be detected in order to strengthenthe signal produced by the microphone. In addition, the position of themicrophone relative to the source of the sound (or near the source ofmultiple sounds) may allow the microphone to pick-up sounds associatedwith a voiding event without being significantly affected by unwantednoises. Unwanted noises are generally sounds that are not associatedwith a voiding event, such as noises produced by the digestive system ofpatient 10 or the environment surrounding patient 10.

The electrical signal generated by the microphone, also referred to asthe sensor signal, is processed to detect voiding events. Processing thesensor signal may, for example, involve processing the signal to removenoise, i.e., unwanted signal components, and processing the signal toidentify a voiding signature. In some embodiments, the voiding signatureincludes a characteristic of an electrical signal that is generatedprior to or during an actual voiding event for a patient or for multiplepatients. The voiding signature may be individualized to a particularpatient or may be applicable to more than one patient. In oneembodiment, the voiding signature used to detecting voiding events is anexample signal generated by the microphone during an actual voidingevent. This example signal is referred to as a signal template and maybe obtained during an initial training or calibration session forvoiding diary 14. The training session may take place in a clinicalenvironment with controlled conditions. For example, the bladder ofpatient 10 may be manually filled and the corresponding voiding eventmay be recorded using automatic voiding diary 14. The signal may beexamined and, if determined to be satisfactory, may be stored and usedas a signal template for detecting voiding events. Multiple signals mayalso be generated during the voiding diary 14 training session andaveraged or otherwise analyzed to generate a signal template that isrepresentative of a voiding event for the patient.

In general, voiding diary 14 may include a processor that amplifies,samples, filters, or otherwise processes the sensor signal to removenoise and identify a voiding signature in the sensor signal. Processingthe sensor signal to remove noise from the signal may enable voidingdiary 14 to detect voiding events more reliably. Noise may be introducedinto the sensor signal by other sounds that are detected by themicrophone or introduced into the sensor signal by the microphoneitself. Thus, voiding diary 14 may include a processor that filters thesensor signal before processing the signal to identify a voidingsignature. The sensor signal may be filtered using various signalprocessing techniques that may be applied to suppress signal componentsat one or more frequencies or range of frequencies.

In one example embodiment, processing the sensor signal to identify avoiding signature in the sensor signal involves temporally correlatingthe sensor signal with a signal template. This may be achieved bysampling the signal with a sliding “window” that defines a time range,and comparing the sample of the signal to a signal template to identifya signal that correlates well with the template. For example, aprocessor of IMD 12 or an external device may perform a correlationanalysis by moving a window along a digitized plot of the amplitude ofthe signal generated by the microphone at regular intervals to define asample of the signal from the microphone. The sample window is slidalong the plot until a correlation is detected between the waveform ofthe signal template and the waveform of the sample of the microphonesignal defined by the window. By moving the window at regular timeintervals, multiple sample periods are defined. The correlation may bedetected by, for example, matching multiple points between the templatewaveform and the waveform of the plot of the signal from the microphoneover time, or by applying any suitable mathematical correlationalgorithm between the sample in the sampling window and a correspondingset of samples stored in the signal template.

In some embodiments, processing the sensor signal to detect voidingevents may be more complex than correlating the sensor signal with asignal template. That is, rather than comparing the entire sensor signalwaveform to the signal template, preliminary signal processing may beapplied to locate portion of the sensor signal that exhibits anincreased likelihood of containing a voiding signature. In fact, thesensor signal may be substantially continuous and generated over largeperiods of time (e.g., over days, weeks or more) and, therefore, includelarge portions that do not correspond to voiding events. As a result, aless complex processing technique may be used to first determine thelikelihood that a portion of the sensor signal contains a voidingsignature. Example processing techniques that may be used during apreliminary analysis of the sensor signal include comparing an amplitudeof the sensor signal to a threshold value. The amplitude may be anamplitude of a particular frequency component. Based on the comparisonto the threshold value, the sensor signal may then be correlated withthe signal template. Using a combination of processing techniques inthis way may conserve battery power, which may be important to the lifeof IMD 12 because it may be expected to operate for weeks, months, oryears on a single power source.

The processing techniques described in this disclosure should not beconsidered limiting of the invention as broadly in this disclosure inany way. Rather, the described processing techniques are merelyexemplary and are intended to provide descriptive examples withouttaking focus away from the primary features of the invention.

When a voiding event is detected, automatic voiding diary 14 storesvoiding information associated with the detected voiding event in localmemory within voiding diary 14 (or IMD 12 in embodiments in which IMD 12includes voiding diary 14). The voiding information may include, forexample, the corresponding portion of the sensor signal that includesthe voiding signature or data that indicates the occurrence of thedetected voiding event. The voiding information may also include atimestamp that corresponds to the time at which the voiding event wasdetected.

Furthermore, in some embodiments, system 2 or, more particularly, IMD12, may include additional sensors (not shown) that monitor othervoiding parameters. Examples of other voiding parameters include thecontent of voided fluid, amount of voided fluid, temperature of voidedfluid, pH of voided fluid, and the like. Accordingly, the additionalsensors may include one or more of impedance sensors, strain gauges,temperature sensors, accelerometers, pH sensors, chemical sensors, andthe like. In such embodiments, automatic voiding diary 14 stores voidinginformation that corresponds to these voiding parameters.

In operation, automatic voiding diary 14 detects voluntary or controlledevents and involuntary or incontinence events. It is typically importantto distinguish between voluntary and involuntary voiding events fordiagnostic purposes. For this reason, the voiding information recordedby automatic voiding diary 14 may include information that identifies adetected event as a voluntary or involuntary event.

In one example embodiment, patient 10 may enter input into patientprogrammer 16 to identify a voiding event as a controlled (i.e.,voluntary) or involuntary event. Patient 10 may, for example, activateone or more buttons, use a stylus, mouse, or other peripheral device toenter input on a graphical user interface. Patient programmer 16 maythen, in response to receiving the input, wirelessly transmitcorresponding identification information (e.g., an indication of whetherthe voiding event was voluntary or involuntary) to automatic voidingdiary 14, which may associate the received identification informationwith the corresponding voiding information. In embodiments in whichautomatic voiding diary 14 transmits the voiding information to patientprogrammer 16 for storage, patient programmer 16 may store theidentification information with or without transmitting the informationto automatic voiding diary 14 and may associate the voiding informationwith the voiding event identification information.

Other techniques for generating identification information for voidingevents may be employed in other embodiments. For example, in oneembodiment, an involuntary voiding event may be detected via one or moresensors incorporated into an undergarment, as described incommonly-assigned U.S. patent application Ser. No. 11/414,504 to John C.Rondoni et al., entitled, “VOIDING DETECTION WITH LEARNING MODE” andfiled on Apr. 28, 2006, the entire content of which is incorporatedherein by reference. The one or more sensors detect the presence offluid which indicates that wetting, and most likely, an involuntaryvoiding event has occurred. In some cases, the sensor may be alsocapable of also detecting fluid pH or other characteristic of the fluidto identify that the fluid is urine. In some embodiments, a pocket thatholds a sensor may also include absorption material that absorbs voidedurine, such that the undergarment is similar to a diaper or protectivegarment.

In some embodiments, automatic voiding diary 14 includes features forstoring voiding information, such as information that identifies adetected voiding event as a voluntary or involuntary event, based on apatient defined action, such as patient 10 tapping on the skin locatedabove IMD 12. Such an example embodiment is illustrated and described indetail in FIGS. 12 and 13.

Various embodiments of automatic voiding diary 14 may be used forstoring and retrieving the voiding information. In one exampleembodiment, automatic voiding diary 14 automatically records voidinginformation in local memory and wirelessly transmits the voidinginformation to patient programmer 16, clinician programmer 18, or both.Automatic voiding diary 14 may transmit the voiding information onrequest, periodically, or when local memory is full. Alternatively,automatic voiding diary 14 may transmit the voiding informationsubstantially continuously.

In some embodiments, patient programmer 16 and clinician programmer 18may retrieve information stored within automatic voiding diary 14 at anytime, for example, by transmitting a wireless request signal toautomatic voiding diary 14. In response to the request, automaticvoiding diary 14 wireless transmits the voiding diary to the appropriateprogrammer which displays the voiding information as a diary or log tothe user.

In other embodiments, automatic voiding diary 14 may transmit the storedvoiding information to programmers 16 and 18 periodically. For example,automatic voiding diary 14 may store voiding information for apre-determined period of time, such as approximately one day, andtransmit the voiding information at the end of the time period. In thiscase, automatic voiding diary 14 may erase or record over thetransmitted voiding information.

In another example, automatic voiding diary 14 may transmit the voidinginformation to one or both of programmer 16 and 18 when local memory isfull or near full capacity. In this case, automatic voiding diary 14 mayerase or record over the stored data when the voiding information hasbeen successfully transmitted. In this way, automatic voiding diary 14may efficiently store voiding information and then “dump” the storedinformation to patient programmer 16 for long term storage.Alternatively, automatic voiding diary 14 may store voiding informationuntil local memory is full or near capacity and transmit all subsequentvoiding information to patient programmer 16.

In an additional example, automatic voiding diary 14 may store little orno voiding information. In this case, diary 14 processes the sensorsignal to detect a voiding event, generate the voiding information, andimmediately transmits the voiding information to patient programmer 16for long term storage. The voiding information may be stored in memoryof diary 14 for a short period of time or may be transmittedsubstantially directly to patient programmer 16. As a result, diary 14,in this case, may require a relatively small amount of memory.

The amount of voiding information stored in automatic voiding diary 14is related to the size of local memory of automatic voiding diary 14.Storing a smaller amount of voiding information in local memory ofautomatic voiding diary 14 allows the size of diary 14 and, thus, thesize of IMD 12 to be reduced. The tradeoff between size and the memorycapacity of automatic voiding diary 14 is a design choice that may beaffected by various other aspects of system 2.

In general, programmers 16 and 18 provide an easy to user interface forviewing the voiding diary and adjusting and/or programming therapy. Theinterface may include tools for navigating and customizing the display.For example, programmers 16 and 18 may provide a scroll bar or othermechanism for navigating the voiding diary and a menu or selectionmechanism for specifying the information that is to be displayed in thevoiding diary. Programmers 16 and 18 communicate with IMD 12 via awireless interface. Example wireless interfaces include wirelesstelemetry, Bluetooth, IEEE 802.11(a), (b), (g), Medical ImplantCommunication Services (MICS), and other standard proprietary wirelessinterfaces.

Patient 10 may use patient programmer 16 to review voiding informationand, in some embodiments, enter input to verify that the information iscorrect. Patient 10 may also user programmer 16 to identify an abnormalintake of fluid, such as a drinking binge, or other event that mayaffect a normal voiding pattern. In this way, patient 10 can use patientprogrammer 16 to ensure that the data stored in voiding diary 14 isaccurate.

For example, after patient 10 voids bladder 22 voluntarily orinvoluntarily, patient 10 may use programmer 16 to verify that automaticvoiding diary 14 detected the event and identify or categorize the eventas a controlled or involuntary event. Verifying the information mayinvolve entering input into programmer 16. For example, patientprogrammer 16 may prompt patient 10 via one or more questions, to whichpatient 10 may enter responses via a user interface of patientprogrammer 16. In the event that patient 10 indicates that the voidinginformation generated by automatic voiding diary 14 is incorrect,automatic voiding diary 14 may discard the incorrect information or,alternatively, store additional data that indicates that patient 10identified the information as being incorrect. Storing this data mayprevent or deter patient 10 from falsely modifying information becauseof embarrassment or other reasons since the clinician will be able todetermine if the information has been modified.

A clinician or other authorized user may use clinician programmer 18 toview the voiding diary and use the voiding diary to identify a conditionafflicting patient 10 or monitor a condition of patient 10. In this way,a clinician can use programmer 18 as a as a diagnostic tool to determinethe appropriate course of treatment, which may or may not includetherapy, or determine the efficacy of treatment. As an example, aclinician may diagnose that patient 10 suffers from nocturnal enuresisby examining the time and nature of voiding events over a period of timewithin the voiding diary. Based on the diagnosis, the clinician mayprescribe therapy in the form of stimulation therapy, drug therapy, or acombination of both. The clinician may then use programmer 18 at a laterdate to view the voiding diary to evaluate the efficacy of thetreatment.

Additionally, a clinician or other authorized user may use clinicianprogrammer 18 to program therapy for patient 10, such as therapy forurinary incontinence. Programmer 18 may transmit one or more programminginstructions to IMD 12 via wireless communication signals. Theprogramming instructions may specify one or more therapy programs thatIMD 12 may deliver therapy in accordance with, where each therapyprogram defines one or more therapy parameters. Examples of therapyparameters include voltage or current amplitude, pulse width or pulsefrequency of electrical stimulation, or drug bolus size, drugconcentration or frequency of drug delivery. The type of therapyparameters depends on the type of therapy delivered by IMD 12.

In the example illustrated in FIG. 1, programmer 18 may be configured toprogram IMD 12 to deliver stimulation therapy, drug therapy, or acombination of both according to one or more therapy programs.Accordingly, in some embodiments, IMD 12 may operate as an implantableneurostimulator (INS) that delivers electrical stimulation therapy forincontinence, while in other embodiments, IMD 12 may be a drug deliverydevice that delivers one or more drugs. In another embodiment, IMD 12may be configured to operate as an INS and a drug delivery device.

Accordingly, therapy element 15 in FIG. 1 may represent a lead carryingone or more electrodes that delivery stimulation in the form ofelectrical pulses or a fluid delivery device, such as a catheter, thatdelivers one or more drugs. In some embodiments, therapy element 15 maycarry electrodes and deliver drugs. Therefore, therapy element 15 shouldnot be considered limiting of the invention as broadly described in thisdisclosure. Instead it is the purpose of therapy element 15 to representone or many therapy elements that deliver therapy from IMD 12 to atarget tissue site within patient 10 in the form of electricalstimulation, drugs, or a combination of both. Therefore, it should beunderstood that FIG. 1 illustrates one of the many example embodimentsthat fall within the scope of the invention as broadly described in thisdisclosure.

Programming therapy may involve selecting or adjusting stimulationparameters or drug delivery parameters. As previously described, examplestimulation parameters include an electrode configuration, a pulse rate,a pulse width, and voltage amplitude or current amplitude. Electrodeconfiguration may refer to both a combination of selected electrodes andpolarities of the electrodes, i.e., as a cathode or anode. Electricalstimulation may be delivered in accordance with one or more programs.Programs may deliver electrical stimulation in a variety of differentmodes, such as a continuous mode, in a series of bursts, or acombination of both. In a similar manner, a clinician may specify a setof parameters for drug delivery that includes selecting which drug ormixture of drugs to deliver, as well as the dosage and rate at which todeliver the selected drug or drugs.

In practice, a clinician may use clinician programmer 18 to select a setof initial therapy parameters and view the voiding diary after patient10 has been subjected to therapy for a period of time. By comparing thevoiding information before and after therapy, the clinician candetermine the efficacy of the treatment and may manually adjuststimulation parameters in an attempt to improve the efficacy of thetreatment. Patient programmer 16 may also provide certain limitedcapabilities to patient 10. For example, patient 10 may use programmer16 to select particular programs or vary the intensity of therapy withina pre-determined range. Further, patient programmer 16 or IMD 12 itselfmay automatically adjust parameters according to the detected voidinginformation. For example, in response to detecting a voiding event andassociating the voiding event with identification information thatindicates the voiding event was involuntary, IMD 12 may automaticallyincrease the intensity of therapy or otherwise adjust the therapyparameters to prevent or reduce involuntary voiding from occurring inthe future.

Stimulation parameter adaptation logic that may be implemented by IMD12, clinician programmer 18 or patient programmer 16 is discussed incommonly-assigned U.S. patent application Ser. No. 11/117,058, entitled,“IMPLANTABLE MEDICAL DEVICE PROVIDING ADAPTIVE NEUROSTIMULATION THERAPYFOR INCONTINENCE,” and filed on Apr. 28, 2005, which is incorporatedherein by reference in its entirety.

It should be understood that system 2 as illustrated in FIG. 1 depictsone of many example systems. That is, system 2, as depicted in FIG. 1,should not be considered limiting of the invention as broadly describedin this disclosure in any way. Instead, the purpose of system 2 is toprovide one example embodiment suitable for broadly describing featuresof the invention.

For example, although FIG. 1 illustrates a single device, i.e., IMD 12,which operates as a therapy delivery device and an automatic voidingdiary, other example systems may include a therapy delivery device and aseparate IMD configured to operate as an automatic voiding diary. Inother words, the therapy delivery device and the automatic voiding diarydevice may be separate devices implanted within the patient, and in someembodiments, the therapy delivery device and automatic voiding diary maycommunicate via wired or wireless communication techniques. The devicesmay be implanted proximate to one another or at different locationswithin the patient. A system that includes a therapy delivery device anda separate automatic voiding diary device may be advantageous when theimplant site for delivering therapy is different than the implant sitefor sensing sounds associated with a voiding event.

In other example embodiments, the automatic voiding diary device may bean external device. In such embodiments, the automatic voiding diarydevice may be incorporated with patient programmer 16 or implemented asa dedicated external device. In either case, it may desirable forpatient 10 to carry the external device substantially continuouslyduring a voiding event information gathering period in order to obtainaccurate voiding information. Additionally, it may be desirable forpatient 10 to carry the external device may be required to be close tothe body for the microphone to generate a signal based on an internal orexternal sound associated with a voiding event. The external device maybe implemented in various ways. For example, the external device may betaped to the skin of patient 10 or an undergarment worn by patient 10,trapped between clothing and the skin of patient 10, attached to theinside of clothing worn by patient 10, sutured to the skin of patient10, held to the skin of patient 10 via a strap, or may otherwise bewearable by patient 10.

In further example embodiments, the automatic voiding diary is notnecessarily used in combination with a therapy delivery device. A systemthat does not include a therapy delivery device may be used as adiagnostic tool to identify and/or monitor the condition of the patientand also to determine if therapy would benefit the patient and whichtherapy would be most beneficial.

It is also contemplated that system 2 or other embodiments of theinvention may be used in combination with one or more additional sensorsthat measure other voiding parameters (i.e., parameters associated withvoiding). The monitoring of electrical signals indicative of voidingparameters may be useful for analyzing a patient's condition or therapyprogram. The additional sensors may include one or more of pressuresensors, impedance sensors, strain gauges, temperature sensors,accelerometers, pH sensors, chemical sensors, and the like. Accordingly,other voiding parameters of interest may include the content of leakedfluid, amount of leaked fluid, temperature of leaked fluid, pH of theleaked fluid, bladder pressure, and so forth. In addition, otherparameters associated with a voiding event may also be monitored andstored in the voiding diary. For example, the activity and posture ofpatient 10 may also be stored in the voiding diary.

Automatic voiding diary 14 may store the output of the additionalsensors in the voiding diary. Accordingly, a clinician may use clinicianprogrammer 18 to view the voiding diary and adjust therapy parametersbased on information relating to one or more voiding parameters storedwithin the voiding diary. Additionally, patient programmer 16, clinicianprogrammer 18, or both may automatically adjust therapy parameters basedon the information in the voiding diary. For example, the clinician orprogrammer 16 and 18 may increase the intensity of stimulation based oneor more voiding parameters, such as the amount of fluid leaked, toprevent or reduce involuntary voiding.

FIG. 2 is a block diagram illustrating various components of IMD 12. Asshown in FIG. 2, IMD 12 includes components for automatic voiding diary14 and components for therapy delivery device 30. In other embodiments,however, the components for automatic voiding diary 14 and therapydelivery device 30 may be enclosed in separate housings. The componentsof automatic voiding diary 14 record information associated with avoiding event without the need for significant interaction from patient10. The components of therapy delivery device 30 deliver therapy topatient 10 to control urinary or fecal incontinence.

Automatic voiding diary 14 includes a sensing circuitry 40, sensor 42,processor 44, memory 46, and clock 48. In general, sensing circuitry 40detects a voiding event based on the output of sensor 42, i.e., theelectrical signal generated by sensor 42. Memory 46 stores voidinginformation under the control of processor 44. Processor 44 may obtain aclock signal from clock 48 to associate a timestamp with the voidinginformation for a detected voiding event stored in memory 46. Memory 46may include any combination of volatile, non-volatile, removable,magnetic, optical, or solid state media, such as read-only memory (ROM),random access memory (RAM), electronically-erasable programmable ROM(EEPROM), flash memory, or the like. Processor 44 may include amicroprocessor, microcontroller, digital signal processor (DSP),application specific integrated circuit (ASIC), field programmable gatearray (FPGA), discrete logic circuitry, or a combination of suchcomponents.

In one embodiment, sensor 42 is a microphone that generates anelectrical signal in accords with internal or external sounds associatedwith voiding events and may be positioned within or on the housing ofIMD 12. Alternatively, sensor 42 may be carried within or on a lead thatextends from IMD 12 or wirelessly coupled to IMD 12. In anotherembodiment, sensor 42 may be a wireless microphone implanted withinpatient 10 and configured to wirelessly communicate with IMD 12. Aspreviously described, sensor 42 may be a crystal microphone, condensermicrophone, a ribbon microphone, or other type of microphone suitablefor implantation within patient 10.

In embodiments in which sensor 42 is a microphone, sensor 42 maygenerate a signal that varies as a function of internal sounds, such assounds produced by bladder 20 (FIG. 1), urinary tract 22 (FIG. 1),rectum (not shown), intestines (not shown), such as sounds produced byfecal matter moving through the bowel during a voiding event, or otherorgans and tissue (not shown) of patient 10 that produce soundsassociated with a urinary or fecal voiding event. In addition to orinstead of generating the signals that vary as a function of internalsounds, sensor 42 may generate a signal that varies as a function ofsounds external to patient 10, such as sounds produced by urine or fecesbeing voided into a toilet, a toilet flushing, fluid exiting the openingof the urethra (FIG. 1), urine or feces being voided into anundergarment, a voice command, or other sound associated with a urinaryor fecal voiding event.

The electrical signal output by sensor 42 may be amplified, filtered,and otherwise processed by sensing circuitry 40. As described above,sensing circuitry 40 may process the signal to remove unwanted signalcomponents to more reliably detect a voiding event. Removing unwantedsignal components, e.g., by filtering the output of sensor 42, mayincrease the likelihood of accurately and reliably detecting a voidingevent. Unwanted signal components may include noise introduced by thesignal path and signal components that result from sounds that are notassociated with a voiding event but are picked up by sensor 42. Thesesounds may include other sounds internal to patient 10, such asdigestive sounds, heart sounds, breathing sounds, and the like as wellas sounds external to patient 10, i.e., sounds produced by theenvironment surrounding patient 10.

To detect a voiding event, sensing circuitry 40 may, for example,utilize a correlation or comparison technique, such as the temporalcorrelation technique described above. In particular, sensing circuitry40 may apply the detection technique to the processed signal in whichthe unwanted signal components have been removed, i.e., the “clean”sensor signal. A correlation technique may involve correlating a sampleof the signal generated by sensor 42 to a signal template stored inmemory 46 in order to detect the presence of a voiding signature in thesignal generated by sensor 42. The signal template may be generatedbased on one or more example signals that are produced by sensor 42during a trial or test period. During the trial or test period, patient10 may be instructed to void under controlled conditions. That is,patient 10 may void at a known time so the signal can be analyzed.

The voiding signature may be characterized by one or more signalcharacteristics, e.g., a particular frequency, amplitude, pattern,trend, or waveform shape, duration, or other signal characteristic. Asan example, a sound associated with a voiding event, such as urine orfeces being voiding into a toilet, may exhibit a particular frequencythat lasts for several seconds or more. As another example, a soundproduced by a muscle that contracts and relaxes to control voiding maybe characterized by one or more pulses of sound at a particularfrequency. In this case, the period of time between pulses may also becharacteristic of the voiding signature.

Sensing circuitry 40 may employ various signal processing techniques todetect a voiding signature in the output of sensor 42. Example,correlation techniques may be performed in a time or frequency domain.In some cases, the frequency domain may be more revealing of signalcharacteristics than the time domain. Frequency analysis techniquesinvolve converting the time domain signal produced by sensor 42 into afrequency signal. This can be achieved by applying a Fast FourierTransform to the output of sensor 42, which is a time domain signal.Frequency analysis techniques may then be used to detect a voiding eventin the frequency signal. Example frequency analysis techniques involvedetermining the power of the signal for particular frequency components.

Additional signal processing techniques may be used to conserve power.That is, because the detection processing techniques may be complex andconsume significant power, sensing circuitry may also employ low powersignal detection techniques. As an example, sensing circuitry 40 maycompare the output of sensor 42 to a threshold value. The thresholdvalue may be the total power of the sensor signal or power of aparticular frequency. This comparison determines the likelihood that aparticular portion of the sensor signal contains a voiding signature. Inother words, when the amplitude of the output of sensor 42 exceeds thethreshold, that portion of the signal has an increased likelihood ofincluding a voiding signature. This may require little processing poweras the technique involves a simple comparison between two values.However, when the signal exceeds the threshold, sensing circuit 40 mayapply more complex and, therefore, power consuming detection techniques.In this way, IMD 12 may operate for several months or years relying onpower from a finite power source (not shown), such as a rechargeable ornonrechargeable battery. In either case, power conservation isdesirable.

In addition to storing a signal template or other voiding signatures,memory 46 of automatic voiding diary 14 may store voiding informationassociated with detected voiding events. In particular, processor 44 maygenerate voiding information based on the output of sensing circuitry 40and store the information in memory 46. In one example, memory 46 storesdata that indicates the occurrence of the detected event. Alternatively,memory 46 may store the actual signal generated by sensing circuitry 40that contains the voiding signature. A clinician may retrieve the storedsignals from memory 46 to analyze the signals. As previously described,memory 46 may also store other voiding information associated with adetected voiding event, such as a time stamp and data that identifies adetected event as a voluntary or involuntary event. In embodiments inwhich IMD 12 includes sensors for recording other voiding information,such as information associated with the contents of voided urine, thisinformation is also stored in memory 46.

Processor 44 may associate a timestamp with a detected voiding event bysending a request signal to clock 48. In response to receiving thecontrol signal, clock 48 generates a signal that represents the time.Alternatively, clock 48 may output the signal to processor 44substantially continuously and processor 44 can examine the signal inresponse to detecting a voiding event. In any case, processor 44 may usethe output of clock 48 to associate a timestamp with voiding informationthat is stored in memory 46.

In addition to voiding information, memory 46 may also storeinstructions for execution by processor 44. Memory 46 may includeseparate memories for storing instructions and voiding information. Inone example embodiment processor 44 and memory 46 may implement looprecorder functionality in which processor 44 overwrites the oldestcontents within memory 46 with new data as storage limits are met,thereby conserving data storage resources. Processor 44 may selectivelyrecord over the data stored within memory 46, such as signals fromsensor 42 that are not indicative of a voiding event. Alternatively,processor 44 and memory 46 may be configured to immediately transmitvoiding information to another device, such as patient programmer 16 orclinician programmer 18. In this case, memory, processing, and powerconsumption overhead in automatic voiding diary 14 can be substantiallyreduced.

As shown in FIG. 2, therapy delivery device 30 includes therapy deliverymodule 32, processor 34, telemetry module 36, and memory 38. Automaticvoiding diary 14 communicates with therapy delivery device 30 and, moreparticularly, telemetry module 36 to transmit voiding information toprogrammers 16 and 18. In particular, automatic voiding diary 14 maycommunicate with processor 34 which controls telemetry module 36.Processor 34 may control telemetry module 36 to transmit voidinginformation to an external device, such as patient programmer 16,clinician programmer 18, or other external device, on a continuousbasis, at periodic intervals, or upon request from an external device,such as patient programmer 16 or clinician programmer 18.

Telemetry module 36 provides a wireless interface with patientprogrammer 16 and clinician programmer 18. The wireless interface may beone of wireless telemetry, Bluetooth, IEEE 802.11(a), (b), (g), or otherstandard proprietary wireless interfaces.

Therapy delivery device 30 delivers therapy to patient 10 for urinaryincontinence via therapy element 15. Therapy element 15 may includeelectrodes carried on one or more leads, electrodes on the housing ofIMD 12, one or more fluid delivery devices, or any combination thereof.Accordingly, therapy delivery module 32 may include an implantablestimulation generator or other stimulation circuitry that deliverselectrical signals, e.g., pulses or substantially continuous signals,such as sinusoidal signals, to patient 10 via at least some of theelectrodes of therapy element 15 under the control of processor 34.

The stimulation energy generated by therapy delivery module 32 may beformulated as stimulation energy for treatment of any of a variety ofurinary or fecal incontinence disorders. Example stimulation therapiesinclude delivering stimulation to nerves, i.e., sacral or pudendalnerves, or directly to a urinary sphincter, where the stimulation causesthe urinary sphincter to constrict and retain urine within the bladder.Electrical stimulation may also be directed to other muscles of thepelvic floor because some of these muscles play a role in controllingurinary voiding events.

An exemplary range of electrical stimulation parameters likely to beeffective in treating urinary or fecal incontinence, e.g., when appliedto the sacral or pudendal nerves, are as follows:

1. Frequency: between approximately 0.5 Hertz (Hz) and approximately 500Hz, such as between approximately 5 Hz and approximately 250 Hz or suchas between approximately 10 Hz and approximately 50 Hz.

2. Amplitude: between approximately 0.1 volts and approximately 50volts, such as between approximately 0.5 volts and approximately 20volts or between approximately 1 volt and approximately 10 volts. Theamplitude may be representative of a biological load between 10 ohms andapproximately 10,000 ohms.

3. Pulse Width: between approximately 10 microseconds and approximately5000 microseconds, such as between approximately 100 microseconds andapproximately 1000 microseconds or between approximately 180microseconds and 450 approximately microseconds.

Other electrical stimulation parameters may also be useful for managingurinary incontinence.

In embodiments in which one or more fluid delivery devices are part oftherapy elements 15, therapy delivery module 32 may include a one ormore fluid reservoirs and one or more pump units that pump fluid fromthe fluid reservoirs to the target site through the fluid deliverydevices. The fluid reservoirs may contain a drug or mixture of drugs.The fluid reservoirs may provide access for filling, e.g., bypercutaneous injection of fluid via a self-sealing injection port. Thefluid delivery devices may comprise, for example, catheters thatdeliver, i.e., infuse or disperse, drugs from the fluid reservoirs tothe same or different target sites within patient 10.

Processor 34 controls therapy delivery module 32 to deliver electricalstimulation via a programmable stimulation signal (e.g., in the form ofelectrical pulses or substantially continuous-time signals) with pulseamplitudes, pulse widths (if applicable), and frequencies (i.e., pulserates) specified by programs of the parameter set selected from memory38. Memory 38 may store therapy parameter sets (i.e., therapy programs)that are available to be selected by the patient for delivery ofelectrical stimulation and/or drug therapy. Memory 38 may also storeschedules for delivering therapy to patient 10. Memory 38 may includeany combination of volatile, non-volatile, removable, magnetic, optical,or solid state media, such as ROM, RAM, EEPROM, flash memory, or thelike.

Processor 34 may also control therapy delivery module to deliver eachpulse according to a different program of the parameter set. In someembodiments, processor 34 may control therapy delivery module 32 todeliver a substantially continuous stimulation waveform rather thanpulsed stimulation. Additionally, processor 34 may automatically adjusttherapy parameters based on voiding information. In this way, voidinginformation from automatic voiding diary 14 may be used in a closed looptherapy adjustment system implemented by therapy delivery device 30 toadjust one or more therapy parameters with the goal of minimizing theoccurrence of any further involuntary incontinence events.

Processor 34 may include a microprocessor, microcontroller, DSP, ASIC,FPGA, discrete logic circuitry, or a combination of such components.Processor 34 is programmed to control delivery of therapy according to aselected parameter set stored in memory 38. Specifically, processor 34controls therapy delivery module 32 to deliver electrical stimulation,drug therapy, or a combination of both. For example, processor 34 maycontrol which drugs are delivered and the dosage of the drugs deliveredor the stimulation parameters with which therapy delivery module 32delivers electrical stimulation therapy to patient 10.

A power source (not shown) delivers operating power to the components ofautomatic voiding diary automatic voiding diary 14 and therapy deliverydevice 30. In embodiments in which automatic voiding diary 14 andtherapy delivery device 30 are located within the same housing, thepower source may be shared among devices 14 and 30. The power source maytake the form of a small, rechargeable or non-rechargeable battery, oran inductive power interface that transcutaneously receives inductivelycoupled energy. In the case of a rechargeable battery of an implanteddevice, the power source similarly may include an inductive powerinterface for transcutaneous transfer of recharge power.

Although FIG. 2 illustrates therapy delivery device 30 and automaticvoiding diary automatic voiding diary 14 as being contained within asingle housing, it should be understood that therapy delivery device 30and automatic voiding diary automatic voiding diary 14 may beimplemented as separate devices. Thus, FIG. 2 should not be consideredlimiting of the invention as broadly described in this disclosure in anyway. However, by incorporating therapy delivery device 30 and automaticvoiding diary automatic voiding diary 14 in a common housing of an IMD(IMD 12), circuitry associated with both devices 14 and 30, such as aprocessor and memory, may be shared and fabricated on a single circuitboard. As a result, the IMD, i.e., IMD 12, may be substantially smallerin size and cost less than separate devices for delivering therapy andstoring voiding information. Additionally, IMD 12 may be implantedwithin patient 10 using fewer incisions and requiring less space thanseparately implanting therapy delivery and voiding diary devices.

FIG. 3 is a functional block diagram illustrating various components ofan external device 60 that may be configured to operate as patientprogrammer 16 or clinician programmer 18. As shown in FIG. 3, externaldevice 60 includes user interface 62, input/out module 63, processor 64,memory 68, telemetry circuit 66, and power source 69. A clinician orpatient 10 may interact with user interface 62 in order to review thevoiding log, modify a component of the voiding log, request voidinginformation from IMD 12, or manually adjust one or more therapyparameters of the stimulation and/or drug therapy. In this way, externaldevice 60 can be viewed as patient programmer 16 or clinician programmer18.

In general, patient programmer 16 provides limited functionality incomparison with clinician programmer 18. As previously described,patient 10 may interact with a patient programmer 16 to view the voidinglog and may be allowed to adjust selected parameters. For example,patient 10 may interact with patient programmer 16 control therapy,e.g., by selecting a program from a limited list of programs oradjusting a parameter within a defined range. Patient 10 may also enterinput that identifies a voiding event as a controlled or involuntaryevent.

In contrast, a clinician may interact with clinician programmer 18 toprogram therapy in IMD 12, for example, by selecting one or more therapyprograms from memory 68. The clinician may also define therapyparameters without being limited to pre-defined ranges. The clinician orpatient 10 may also interact with device 60 to receive diagnosticinformation from IMD 12, such as the remaining life of the power sourceor electrode impedance measurements if therapy element 15 or the housingof IMD 12 includes one or more sensing or stimulation electrodes.

User interface 62 may include a display and one or more input buttonsthat allow clinician programmer 18 to receive input from the clinician.The screen may be a liquid crystal display (LCD) or touch screen. Theinput buttons may include a touch pad, increase and decrease buttons,emergency shut off button, an alphanumeric keypad or a reduced set ofkeys associated with particular functions or other buttons needed tocontrol the stimulation and/or drug therapy. Processor 64 may presentthe voiding log via the display of user interface 62 and the clinicianmay review the voiding log of voiding information to determine aneffective treatment or adjust therapy parameters for the currentlyselected therapy.

Processor 64 may include a microprocessor, microcontroller, DSP, ASIC,FPGA, discrete logic circuitry, or a combination of such components.Processor 64 controls user interface 62, retrieves data from memory 68and stores data, such as voiding information, within memory 68.Processor 64 also controls the transmission of data through telemetrymodule 66 to IMD 12. Specifically, processor 64 controls receivingvoiding information from automatic voiding diary device 14 andtransmission of therapy programs to therapy delivery device 30.

Processor 64 may receive parameter set selections made by patient 10 ora clinician via user interface 62, and may either transmit the selectionor the selected parameter set to IMD 12 via telemetry module 60 fordelivery of drug therapy and electrical stimulation according to theselected parameter set. Telemetry module 66 includes a transceiver forwireless communication, appropriate ports for wired communication orcommunication via removable electrical media, or appropriate drives forcommunication via removable magnetic or optical media. Telemetry module60 may support both wireless communication with IMD 12 and wirelesscommunication with another programmer or external device.

In some embodiments, external device 60 may include input/output module63 in addition telemetry module 66. Input/output module 63 allowsprocessor 64 to communicate with another programmer. For example, whereexternal device 60 stores parameter sets in memory 68, processor 64 mayreceive parameter sets from another programmer via input/output module63 during programming by a clinician.

Memory 68 may include any combination of volatile, non-volatile,removable, magnetic, optical, or solid state media, such as ROM, RAM,EEPROM, flash memory, or the like. Memory 68 includes operationinstructions for processor 64 and voiding information. In embodiments,where therapy is also delivered, memory 68 may also store therapyparameters to define the therapy. Memory 68 may also include a historyof all user inputs and changes to the voiding information for laterreview if necessary. In addition, memory 68 may store voidinginformation received from automatic voiding diary 14 (FIG. 2).

Telemetry module 66 allows the transfer of data to and from IMD 12.Telemetry circuit 66 may receive voiding information automatically fromautomatic voiding diary device 14 as voiding events are detected, at ascheduled time, when memory within IMD 12 is full, or when requested bya clinician through user interface 62. Power source 69 may be arechargeable battery, such as a lithium ion or nickel metal hydridebattery. Other rechargeable or conventional, nonrechargeable batteriesmay also be used. In some cases, clinician programmer 18 may be poweredby a connection to an alternating current outlet.

FIG. 4 is a schematic diagram illustrating a system 80 including atherapy delivery device 82 that delivers therapy to patient 10 fortreating urinary incontinence and an implantable automatic voiding diary84. As shown in FIG. 4, therapy delivery device 82 and automatic voidingdiary device 84 are separate IMDs that wirelessly communicate with oneanother. Alternatively, therapy delivery device 82 and implantableautomatic voiding diary 84 may be coupled via a wired connection (e.g.,a conductor electrically coupling therapy delivery device 82 toimplantable automatic voiding diary 84). With respect to FIG. 4, therapydelivery device 82 and automatic voiding diary 84 are substantiallysimilar to therapy delivery device 30 and automatic voiding diary 14,respectively, of FIG. 1. Consequently, system 80 operates insubstantially the same manner as system 2 shown in FIG. 1.

In one embodiment, automatic voiding diary 84 includes a microphone (notshown) that generates an electrical signal based on a sound associatedwith a voiding event and a memory that stores voiding information fordetected voiding events. Therefore, it should be understood thatautomatic voiding diary 84 generally operates in similar fashion asautomatic voiding diary 14 in FIGS. 2 and 3. For this reason, thedetails of operation of device 84 are not described in detail to avoidredundancy in this disclosure.

In the illustrated example of FIG. 4, therapy delivery device 82 may beimplemented as an INS, drug pump, or other therapy delivery device wellknown in the field of IMDs for delivering stimulation therapy, drugtherapy, or a combination of both. Additionally, similar to therapyelements 15, therapy element 85 is coupled to therapy delivery device 82and may represent a lead carrying one or more electrodes that deliverystimulation in the form of electrical pulses or a fluid delivery device,such as a catheter, that delivers one or more drugs. Although only onetherapy element for therapy delivery device 82 is illustrated in FIG. 4,in some embodiments, therapy delivery device 82 may include more thanone therapy element 85. For example, in some embodiments, system 80 mayinclude more than one lead that each carry electrodes for deliveringstimulation therapy, more than one catheter that each deliver one ormore drugs, or any combination thereof. Additionally, therapy element 85may, in some embodiments, carry electrodes and deliver drugs fortreating urinary incontinence.

With respect automatic voiding diary device 84, however, device 84 maybe configured to have a capsule-like shape. That is, the housing ofdevice 84 may have the shape of a rounded capsule and may have a lengthof approximately 2 centimeters (cm) to approximately 5 cm, a width ofapproximately 1.5 cm to approximately 5 cm, and a thickness ofapproximately 0.5 cm to approximately 2.5 cm. Alternatively, thecapsule-like shape may exhibit a circular cross-section, in which device84 may have a diameter of approximately 0.5 cm to approximately 1.5 cm,rather than width and height dimensions. The shape and size of device 84may facilitate implantation at locations within patient 10 that promotesensing of sounds associated with a voiding event. Accordingly, in anexample embodiment, voiding diary device 84 may be configured to bepercutaneously introduced into patient 10. In such an embodiment, thesize and shape of voiding diary device 84 enables it to be introducedusing an introducer device, such as a needle.

Although not shown in FIG. 4, the microphone used by automatic voidingdiary device 84 may be located on or within the housing of device 84.Alternatively, the microphone may be carried on a lead (not shown) thatextends from the housing of device 84. The microphone may be locatedmedially along the length of the lead or may be located at the distalend of the lead. As previously described, positioning the microphone atthe distal end of the lead may enable the microphone to be implanted ata particular site within patient 10 that results in an improved qualityof signal generated by the microphone.

In any case, automatic voiding diary device 84 operates as a wirelesssensor that is configured to transmit voiding information to therapydelivery device 82 in addition to or instead of transmitting voidinginformation to patient and clinician programmers 16 and 18. For example,therapy delivery device 82 may control or adjust therapy parametersbased on voiding information received from automatic voiding diarydevice 84. In another example, although not explicitly shown in FIG. 4,automatic voiding diary device 14 may wirelessly transmit voidinginformation to patient and clinician programmers 16 and 18 fordiagnostic purposes. That is, a patient or clinician may use programmers16 and 18 to view voiding information received from automatic voidingdiary as previously described. Thus, automatic voiding diary 14 may beimplanted within patient 10 to generate voiding information for thepurposes of patient diagnosis both alone or in combination with therapydelivery device 82.

System 80 may exhibit certain advantages. For example, therapy deliverydevice 82 and automatic voiding diary 84 may be implanted at differentlocations within patient 10. For example, therapy delivery device 82 maybe implanted in a subcutaneous pocket in the lower back or abdomen ofpatient 10 whereas automatic voiding diary device 84 may be implantedproximate to bladder 20, urinary tract 22, or other location proximateto the urinary system of patient 10. Alternatively, therapy deliverydevice 82 may be implanted in a subcutaneous pocket in the lower back orabdomen of patient 10 whereas automatic voiding diary device 84 may beimplanted proximate to a portion of the intestines, rectum, or otherlocation proximate to the gastrointestinal tract of patient 10.Implanting automatic voiding diary device 84 at a location proximate tobladder 20, as shown in FIG. 4, may increase the likelihood andreliability of detecting a voiding event based on the electrical signalgenerated by the microphone of device 84. That is, by implanting device84 at a location different than that of device 82, the electrical signalgenerated by the microphone of device 84 may have improved quality. Inother words, the electrical signal generated by the microphone may becloser to the source of the sounds associated with a voiding event and,at the same time, exposed to a lesser amount of unwanted noise.

FIG. 5 is a block diagram illustrating various components of automaticvoiding diary 84. In the illustrated example of FIG. 5, device 84includes sensing circuitry 90, sensor 92, processor 90, telemetry module96, memory 98, clock 112, and power source 114. Sensing circuitry 90,sensor 92, processor 94, telemetry module 96, memory 98, and clock 112are substantially similar to sensor 42, sensing circuitry 40, processor44, telemetry module 36, memory 46, and clock 48, respectively.

Accordingly, sensor 42 may be a microphone, such as a crystalmicrophone, condenser microphone, a ribbon microphone, or other type ofmicrophone suitable for implantation within patient 10 that generates anelectrical signal based on a sound associated with a voiding event, aspreviously described. Sensing circuitry 90 generally processes thiselectrical signal to detect voiding events and memory 98 stores thevoiding information under the control of processor 94. Processor 94 mayalso generate timestamps, information that identifies detected voidingevents as voluntary or involuntary events, and other informationassociated with detected voiding events. As previously described,processor 94 may generate a timestamp based on a clock signal receivedfrom clock 112.

In response to detecting a voiding event, processor 94 may store inmemory 98 the raw output of sensor 92, the processed signal that isproduced by sensing circuitry 90, or data that simply indicates that avoiding event was detected. In addition, processor 94 may also associateand store a timestamp with the voiding information stored in memory 98based on a clock signal received from clock 112. Further, processor 94may also store as part of the voiding information associated with adetected voiding event, data that identifies the detected event as acontrolled or involuntary event. In this case, processor 94 may generatethis data based on a signal received from input mechanism 110. Processor94 and memory 98 may implement loop recorder functionality or may beconfigured to transmit voiding information to device 82 or an externaldevice, such as patient or clinician programmers 16 and 18.

Telemetry module 96 may transmit voiding information to an externaldevice in accordance with wireless telemetry protocols, Bluetooth, IEEE802.11(a), (b), (g), or other standard proprietary wireless protocols.Telemetry module 96 may also receive information from an externaldevice. For example, telemetry module 96 may receive updated signalmodels or templates to use for detecting a voiding signature in thesignal output by sensor 92.

FIG. 6 is a schematic diagram illustrating a system 120 that includestherapy delivery device 82 and patient programmer and automatic voidingdiary 124, which is referred to hereafter as device 124. In general,system 120 operates in a similar fashion as systems 2 and 80 in FIGS. 1and 4, respectively, but provides an automatic voiding diary as anexternal device instead of a device implanted within patient 10. Inparticular, therapy delivery device 82 in FIG. 6 corresponds to therapydelivery device 82 illustrated in FIG. 4 and delivers therapy to patient10 for urinary or fecal incontinence. Device 124, however, is configuredto operate similar to patient programmer 16 and include thefunctionality of automatic voiding diary 14 and 84. That is, device 124operates as an automatic voiding diary as well as a patient programmeras previously described in this disclosure.

Device 124 includes a microphone that may be positioned on or within thehousing of device 124. Since device 124 is an external device, patient10 may carry device 124 throughout the course of a day. Microphoneincorporated in device 124 is positioned external to patient 10, andthus, may be unlikely to detect or generate an electrical signalindicative of internal sounds associated with a voiding event, such assounds produced by bladder 20, urinary tract 22, rectum (not shown),intestines (not shown), or other organs and tissue (not shown) thatproduce a sound associated with a urinary or fecal voiding event.However, the microphone incorporated within device 124 may pick up,i.e., generate an electrical signal based on, external sounds associatedwith a voiding event. These sounds may include but are not limited to asound produced by urine or feces being voided into a toilet, a toiletflushing, fluid exiting urinary tract 22, fluid or feces being voidedinto an undergarment, a voice command, or other sound produced bypatient 10 or the environment that is associated with a urinary or fecalvoiding event.

Device 124 may have the shape and size of a personal electronic device.For example, device 124 may be described as a handheld electronic devicethat is sized to be held in one hand and can easily be carried in thepocket of a user. Device 124 may or may not include a LCD screen fordisplaying a user interface with which the user can interact to viewvoiding information or perform limited programming functions, such asadjust therapy parameters within a pre-defined range of values.Generally, the size of device 124 may not be substantially larger thanthe size or patient programmer 16. This is because few components areneeded to add the functionality provided by automatic voiding diarydevice 14, i.e., to add the functionality of an automatic voiding diary.

Generally, patient 10 carries device 124 throughout the day. However,unlike patient programmer 16, it may be particularly important to carrydevice 124 close to the body of patient 10. This is because the distancebetween device 124 and, more particularly, the microphone carried bydevice 124, and the body of patient 10 may affect the performance, i.e.,the ability of device 124 to detect voiding events. For this reason, itmay be advantageous to attach device 124 to the clothing of patient 10or directly to patient 10 to reduce the distance between the source ofthe sound and the microphone. This may also minimize the possibility ofpatient 10 forgetting device 124 at home or at other places, anddecreases any burden to patient 10 to carry patient programmer andautomatic voiding diary device 124.

In order to increase the likelihood of reliably detecting soundsassociated with a voiding event, device 124 may include elements forattaching patient programmer and automatic voiding diary 124 to theclothing of patient 10. Example elements may include clips, pins, bands,adhesives such as tape or Velcro, and the like. As an example, device124 may include a clip, pin, or band for attaching device 124 to thewaist band of pants or shorts.

As shown in FIG. 6, patient programmer and automatic voiding diary 124wirelessly communicates with clinician programmer 18 and therapydelivery device 82. Accordingly, patient programmer and automaticvoiding diary 124 includes the communication features previouslydescribed with respect to patient programmer 16 and device 14. Forexample, device 124 may transmit voiding information to clinicianprogrammer 18 for review by a clinician. Therapy delivery device 82 mayalso receive voiding information from device 124 for adjusting therapyparameters.

In this way, device 124 automatically tracks voiding events and can beused by patient 10 to review voiding information or provide other input,such as input indicating a voiding event was voluntary or involuntary.Automatically recording voiding events eliminates the need for patient10 to manually track voiding events, e.g., by entering events in awritten or electronic diary. In embodiments in which patient 10 usesdevice 124 to review voiding information, device 124 includes a display,such as an LCD screen, for presenting the voiding information to patient10 as a voiding diary. Patient 10 may also be able to confirm that anevent was detected correctly prior to the event being written to thediary. Device 124 may also enables patient 10 to enter additionalinformation associated with the voiding event. As an example, patient 10may interact with device 124, e.g., by depressing one or more buttons,selecting an item from a menu, or the like, to identify a voiding eventas a controlled or involuntary event. Thus, device 124 combines theoperational features of patient programmer 16 and automatic voidingdiary 14 without substantially increasing the size of patient programmer16.

It should be understood that the operational features of automaticvoiding diary 14 and 84 may also be implemented in handheld electronicdevices other than a patient programmer. For example, a personal digitalassistant (PDA), cell phone, watch, or personal electronic device may beconfigured to operate as an automatic voiding diary. In such examples,however, patient 10 may also carry a patient programmer, although theautomatic voiding diary may be useful without a patient programmer.

FIG. 7 is a block diagram illustrating various components of device 124.As described with respect to FIG. 6, device 124 combines the operationalfeatures of patient programmer 16 and an automatic voiding diary, suchas automatic voiding diary 14 or 84. Accordingly, device 124 includessimilar components to patient programmer 16 and device 14.

In the illustrated example of FIG. 7, patient programmer 124 includessensing circuitry 130, sensor 132, processor 134, telemetry module 136,memory 138, clock 142, power source 144, user interface 146, andinput/output module 147. With respect to FIG. 5, sensor 132, sensingcircuitry 130, processor 134, telemetry module 136, memory 138, clock142, and power source 144 correspond to sensor 92, sensing circuitry 90,processor 94, telemetry module 96, memory 98, clock 112, and powersource 114, respectively. In addition, processor 134, telemetry module136, memory 138, and user interface 146 and input/output 147 correspondto processor 64, telemetry module 66, memory 68, user interface 62 andinput/output module 63 of FIG. 3, respectively.

FIG. 8 is a conceptual diagram illustrating a system 170 including anexternal device 174 configured to operate as an automatic voiding diary.In FIG. 8, device 174 may generally be configured to be easily carriedor worn by patient 10. For example, device 174 may be attached to orotherwise carried by a belt 172 as shown in FIG. 8. Thus, device 174 mayhave a reduced size that facilitates the discrete attachment to the bodyor clothing of patient 10.

Similar to the previously described automatic voiding diary devices,device 174 includes a microphone (not shown) that generates anelectrical signal based on sounds associated with voiding events. Themicrophone may be positioned on or within the housing of device 174.Device 174 generally does not include features, such as an interface,for displaying voiding information to patient 10 or receiving input frompatient 10. Rather, device 174 wirelessly transmits recorded voidinginformation to one or both of patient and clinician programmers 16 and18. Accordingly, device 174 may be viewed as providing similaroperational features as automatic voiding diary devices 14 and 84.

However, in contrast to devices 14 and 84, device 174 is not implantedwithin the body of patent 10. Consequently, device 174 may beparticularly useful for patients that are not good candidates forimplantable medical devices. Device 174 may also be useful as apreliminary diagnostic device to determine if a patient would benefitfrom an implantable automatic voiding diary device and/or implantabletherapy delivery device. Furthermore, device 174 may also be usefulduring a trialing period (or a “calibration mode”) in which externalsounds associated with voiding, or voiding characteristics of theelectrical signal generated by the microphone within device 174 aredetermined. The external sounds may differ, depending on the life styleof patient 10, and different patients may generate different externalsounds or be subjected to different environmental sounds during voidingevents. Accordingly, device 174 may be used to “train” the processorwithin device 174 or another computing device to recognize certainsounds or electrical signals as indicative of a voiding event.

It is important that device 174 be attached to the body or clothing ofpatient 10 to increase the likelihood of reliably detecting soundsassociated with a voiding event. For this reason, device 174 may includeelements for attaching device 124 to the clothing or body of patient 10.As examples, device 174 may include a clip, pin, or band for attachingdevice 174 to the waist band of pants or shorts. As another example,device 174 may include a strip of Velcro that attaches to acorresponding strip of Velcro on an undergarment. In this example, theVelcro may be strategically positioned, e.g., near the groin region ofpatient 10. In this way, device 174 may be more likely to detect soundsassociated with a voiding event.

Placement of device 174 near an undergarment may be particularlyadvantageous for detecting involuntary events in which fluid is voidedinto the undergarment. That is, the sound of fluid being voided into anundergarment may be difficult to detect with an external or internaldevice because of the reduced volume of sound in comparison to othersounds (such as the sound produced by flushing a toilet), andaccordingly, positioning the microphone to the source of the sound mayincrease the possibility of the microphone capturing sounds of fluidbeing voided into an undergarment. By attaching device 174 to theundergarment at a location proximate to the opening of the urethra ofpatient 10, the distance between the source of the sound and device 174is reduced. Additionally, device 174 may also be able to detect othernoises, such as sounds produced by fluid being voided into a toilet orthe sound produced by a toilet flushing, at this location.

FIG. 9 is a block diagram illustrating various components of device 174.In the illustrated example of FIG. 9 device 174 includes sensingcircuitry 180, sensor 182, processor 184, telemetry module 186, memory188, clock 192, and power source 194. These components are substantiallysimilar to sensor 92, sensing circuitry 90, processor 90, telemetrymodule 96, memory 98, clock 112, and power source 114, respectively, ofautomatic voiding diary 84 of FIG. 5.

FIG. 10 is a flow diagram illustrating an example technique forautomatically detecting voiding events via a microphone, and recordingvoiding information for the detected voiding events. The exampletechnique may be employed by any of previously described devices 14, 84,124 and 174. Although various devices have been described in thisdisclosure for generating a voiding diary, FIG. 10 will be describedwith respect to automatic voiding diary device 14. It should beunderstood, however, that the flow diagram of FIG. 10 may also be usedto describe the operation of other automatic voiding diary devices thatgenerate a signal indicative of a sound associated with a voiding event,such as devices 84, 124, and 174.

The technique begins with device 14 and, more particularly, themicrophone associated with device 14 generating an electrical signalbased on sounds associated with voiding events (190). As previouslydescribed, a sound associated with a voiding event may be an internal orexternal noise that can be translated into an electrical signal by amicrophone. Internal sounds may includes sounds produced by bladder 20,urinary tract 22, rectum (not shown), intestines (not shown), or otherorgans and tissue (not shown) of patient 10 that produce a soundassociated with a urinary or fecal voiding event. External sounds may besounds produced by patient 10 or the environment during a voiding event,such as a sound produced by urine or feces being voided into a toilet, atoilet flushing, fluid exiting urinary tract 22, urine or feces beingvoided into an undergarment, a voice command, or other sound associatedwith a urinary or fecal voiding event.

Generally, device 14 generates an electrical signal substantiallycontinuously. Thus, only portions of the electrical signal generated bysensor 92 include a voiding signature. For this reason, device 14processes the electrical signal to detect a voiding event (192). Aspreviously described, processing the signal may involve comparing thesignal to a signal template stored in memory. Processing the signal mayfurther involve processing the signal to remove unwanted signalcomponents and utilizing low power detection techniques, as previouslydescribed.

In some embodiments, device 14 does not generate the electrical signalsubstantially continuously, but may enter a sleep state in which device14 does not generate the signal if an amplitude the signal remains belowa threshold value for a threshold amount of time, thus indicating thatpatient 10 is sleeping or otherwise not likely to void. The sleep statemay help conserve energy. During the sleep state, device 14 may onlygenerate the signal periodically, such as about every second, aboutevery minute, or about every hour. Device 14 may be “awoken” from thesleep state and enter an active state upon detecting a sound (via theelectrical signal) that is above an awake threshold. The sleepthresholds and awake thresholds may be determined by a clinician or amanufacturer of device 14. Alternatively, device 14 may include anaccelerometer that generates a signal which causes device 14 to “wakeup” from the sleep state. The accelerometer may generate the “awaken”signal in response to detecting motion during the night hours ordetecting motion after extended periods of time of inactivity.

In some cases, device 14 may be used to detect voiding events during asleep state (e.g., to diagnose nocturia). In such cases, the clinicianmay program device 14 to not enter the sleep state.

After processing the signal, device 14 determines if a voiding event hasbeen detected (194). In the event that a voiding event has not beendetected (“NO” branch of decision block 194), device 14 generates asignal based on detected sounds (190) and processes the signals todetect a voiding event (192). In this way, steps 190, 192, and 194 forma loop that executes until a voiding event is detected (“YES” branch ofdecision block 194).

In response to detecting a voiding event, device 14 stores voidinginformation (196). The voiding information may include a portion of theelectrical signal that includes a voiding signature, data that indicatesa detected voiding event, a timestamp associated with a detected voidingevent, and data that identifies the voiding event as a voluntary orinvoluntary event. The voiding information may be stored in local memoryor transmitted to an external device, such as patient or clinicianprogrammers 16 and 18, to be stored. After recording the voidinginformation in memory 46 (FIG. 2), device 14 may continue generating theelectrical signal based on detected sounds (190), and so forth.

The voiding information stored within memory 46 may be displayed to thepatient or a clinician via programmers 16 and 18, respectively (198).The patient may review the information to verify that the information iscorrect. A clinician may review the information to monitor and diagnosea condition of the patient and to adjust therapy parameters.

FIG. 11 is a flow diagram illustrating an example technique forcalibrating an automatic voiding diary to detect voiding events. Similarto the flow diagram illustrated in FIG. 10, the example technique inFIG. 11 is described with respect to automatic voiding diary 14 (device14), but may be employed by any of the previously described devicesincluding a microphone for generating a signal indicative of detectedsounds, i.e., devices 84, 124, and 174.

In particular, FIG. 11 shows a calibration mode 200 and an operationalmode 210. In the calibration mode, a sensor signal, i.e., an electricalsignal generated by the microphone associated with device 14, ismonitored (202). The sensor signal is monitored in a controlledenvironment. For example, patient 10 may be given fluids to drink for aperiod of time to induce a natural voiding event. Alternatively, aclinician may actively fill the bladder via a catheter to induce orsimulate an actual voiding event.

As yet another alternative, if device 14 is configured to generate asignal indicative of external sounds, the calibration mode 200 in whichdevice 14 “learns” which sounds are associated with voiding events maybe conducted outside of the clinician's office. As previously discussed,the external sounds associated with voiding events may differ based onthe patient.

As the sensor signal is monitored, patient 10 provides input when thevoiding event occurs (204). When input is not received, steps 202 and204 are repeated, i.e., the process continues to monitor the receivedsensor signal for received patient or clinician input.

When input is received (“YES” branch of decision block 204), device 14defines a voiding signature based on the electrical signal (206).Defining the voiding signature may involve storing a waveform of thatparticular portion of the electrical signal in memory (208) as a voidingsignature template for correlation with subsequently received signals toidentify voiding events. The voiding signature may include one or morecharacteristics of the sensor signal, such as amplitude, frequency, timeintervals, morphology, or the like.

Upon defining the voiding signature, device 14 may be used in anoperational mode 210 to detecting voiding events. For example, in oneembodiment, device 14 monitors the sensor signal received from themicrophone (212) of device 14 and compares the sensor signal to thestored signal template to determine whether there is a substantialsignal template match (214). If there is not a match, the sensor signalcontinues to be monitored. If a signal template match is detected (“YES”branch of decision block 214), however, device 14 records voidinginformation (216) and, in some embodiments, takes a specified action(218). The specified action may be, for example, transmitting thevoiding information to an external programmer or adjusting therapyparameters based on the voiding information.

FIG. 12 is a conceptual cross-sectional view of an abdominal region 204of a patient, such as patient 10. Abdominal region 204 includesepidermis 206 and subcutaneous tissue 208. FIG. 12 further shows adevice 212 implanted within subcutaneous tissue 208. In general, device212 operates similar to previously described automatic voiding diarydevices 14 and 84, but includes additional features for providing a userfriendly and accurate implantable automatic voiding diary device.Alternatively, device 212 may detect urinary or fecal voiding eventsusing other techniques known in the art. For example, device 212 maydetect urinary voiding events using one or more pressure sensors, flowsensors, strain gauges, sensing electrodes, or other types of sensorsused for detecting urinary voiding events and detect fecal voidingevents using one or more pressure sensors, strain gauges, sensingelectrodes, such as electromyography sensors for detecting detrusor orbowel muscle contraction, or other types of sensors used for detectingfecal voiding events. In any case, when device 212 detects a voidingevent or receives a signal from another device that detects voidingevents, device 212 records voiding information in response to receivinga patient defined action. The voiding information may be informationthat identifies a detected voiding event as a voluntary or involuntaryevent. In FIG. 12, the patient defined action is the “tapping” of finger202 on skin 218 located above or superior to device 212.

Because device 212 operates similar to the previously describedautomatic voiding diary devices, these common features are not describedin detail with respect to FIG. 12. Rather, the purpose of FIG. 12 is todescribe the additional features of device 212. Unlike the previouslydescribed automatic voiding diary devices, device 212 includes an inputmechanism that generates an electrical signal based on the patientdefined action, i.e., tapping. This signal is processed and associatedwith a detected voiding event (e.g., detected via a microphone withindevice 212) to generate data that identifies a detected voiding event asa voluntary or involuntary event. This data is also referred to as“identification information” in this disclosure and may be stored inmemory of device 212, or an external device, as part of the voidinginformation that forms the voiding diary.

Identification information may be useful for diagnosing the condition ofpatient 10 and determining the efficacy of therapy that is delivered tothe patient. For example, determining the number of incontinence eventsand/or the ratio of incontinence events to involuntary events may becritical to accurately diagnose the patient and determine the efficacyof therapy. In addition, the identification information may be used in aclosed-loop therapy adjustment system to adjust one or more therapyparameters. For example, if the identification information identifies aninvoluntary voiding attempt, the one or more therapy parameters may beadjusted accordingly to better control the patient's urinary or fecalincontinence.

The input mechanism that generates the electrical signal based on thepatient defined action may be, for example, a multiple or single axisaccelerometer or a strain gauge that produces a detectable change inelectrical resistance based on the extent of deformation of the straingauge, although other input mechanisms may be possible. For example, insome embodiments, a microphone may be used to detect the patient definedaction, such as the tapping. The microphone may be similar to themicrophone described above with respect to FIG. 2. The tapping of finger202 on skin 218 refers to the motion of patient 10 pressing finger 202downward into skin 218 located above or superior to device 212 andsubsequently releasing finger 202 from skin 218, as indicated by thearrows in FIG. 12. Tapping skin 218 in this manner causes epidermis 206and subcutaneous tissue 208 to compress and/or deflect in the directionof motion. This causes device 212 to be displaced from original location204A to temporary location 204B for a period of time before returning tooriginal location 204A. Original location 204A is indicated in FIG. 12by the solid outline of device 212 while the temporary location 204B isindicated in FIG. 12 by the dashed outline of device 212′. When finger202 is released from skin 218, epidermis 206 and subcutaneous tissue 208return to their normal state and device 212 returns to its originallocation 204A. The distance device 212 travels along the axis of motionis represented by distance 210 in FIG. 12. The distance of this motionis labeled 210 in FIG. 12. Distance 210 may be approximately 1millimeter (mm) to approximately 20 mm or on the order of approximately1 mm. Accordingly, the accelerometer may be positioned on or within thehousing of device 212 and may be capable of detecting movement of thedevice on the order of approximately 1 mm to approximately 20 mm.

Using a single axis accelerometer as the input mechanism for device 212may provide certain advantages. For example, since a single axisaccelerometer translates motion along a single axis into an electricalsignal, it may be less likely to misconstrue other motions as tapping.In other words, the single axis accelerometer generates an electricalsignal based on motion along a single axis. Therefore, motion along anyother axis is not translated into an electrical signal. As a result, itis less likely that other patient motions that result in motion ofdevice 212, such as jumping, sitting, standing, and the like, will bemisinterpreted as input, i.e., tapping or other motions for identifyinga voiding event as a controlled or involuntary event. Further, a singleaxis accelerometer may provide a less complex and more power efficientimplementation than would otherwise be possible with a multiple axisaccelerometer.

In operation, one or more taps may be used to identify a voiding eventas a controlled or involuntary event. Each tap may also be referred toas an input event in this disclosure. In one example embodiment, asingle tap may indicate that a voiding event was a involuntary event andtwo or more taps may indicate that a voiding event was an involuntary orincontinence event. In other embodiments, any two tapping patterns couldbe used to identify an involuntary voiding event from a voluntary event.

In other example embodiments, other characteristics of one or more inputevents may be used to identify a voiding event as a controlled orinvoluntary event. Other example characteristics include the duration ofan input event, frequency of input events, pattern of input events, andthe like. The duration of an input event is defined in this disclosureas the duration of time for which device 212 is displaced to temporaryposition 204B (indicated as device 212′ in FIG. 12). In other words, theduration of the input event may be viewed as the period of time that thepatient presses finger 202 into skin 218. For example, when device 212detects that it was displaced to temporary position 204B for a thresholdamount of time or greater, device 212 may record voiding informationthat indicates a voiding event was involuntary. On the other hand, whendevice 212 detects that it was displaced to temporary position 204B, butfor less than a threshold amount of time, device 212 may record voidinginformation that indicates a voiding event was voluntary. In this way,an input event with a first predefined duration may be used to identifya controlled voiding event and an input event with a second predefinedduration longer than the first predefined duration may be used toidentify an involuntary voiding event. As an example, the firstpredefined duration may be within a range of approximately 1 second orless and the second predefined duration may be within a range ofapproximately greater than approximately 1 second and less thanapproximately 3 seconds. Other time durations may be used. In this way,a single input event can be used to identify a voiding event as acontrolled or involuntary event.

Alternatively, instead of using the duration of an input event toidentify the nature of a voiding event, the duration of an input eventmay be used to increase the reliability of detecting input events. Insuch cases the duration of an input event may be used to distinguish aninput event from other motions that may be misconstrued as acharacteristic input provided by the patient. In other words, sinceother motions of the patient, such as scratching, fastening a seat belt,and the like, may mimic the tapping input with respect to pressing skin218 for a period of time, requiring an input event to have a definedduration may limit false positives.

In order to distinguish a characteristic “tap” from other movements thatmay be misconstrued as a characteristic input, the “tap” may involvepressing at location 212 for a period of time. By pressing for acharacteristic period of time, this input may be distinguished fromother actions that may be misconstrued as characteristic input. Thismay, for example, be useful for distinguishing displacement caused bysitting and standing. Sitting and standing may displace device 212 inthe same way a characteristic patient input, but displaces device 212for an extended period of time. In other words, a characteristic inputdisplaces device 212 from its current position to a temporary positionfor a relatively short period of time, followed by returning to theoriginal position. In contrast, sitting down may displace device 212from its original position to a second position. Device 212 may,however, remain in this second position for a relatively extended periodof time in comparison to the characteristic input. Again, the durationdevice 212 remains in the temporary position 204B may be compared to athreshold time period stored within a memory of device 212 in order todetermine whether an input was intended to be an input.

The frequency of input events may be used to identify the nature of avoiding event by using different frequencies to distinguish between acontrolled and an involuntary event. The frequency is defined as thetime between two or more successive taps or input events. Therefore, ainvoluntary event may be identified by two or more taps characterized bya first frequency and an involuntary event may be identified by two ormore taps characterized by a second frequency greater than the firstfrequency. For example, a involuntary event may be identified by twotaps separated by a period of time of approximately half a second orless. In contrast, an involuntary event may be identified by two tapsseparated by a period of time of approximately a second or more. In thiscase, the involuntary event may be viewed as being similar to a “doubleclick” of a mouse. In this way, multiple taps are required to provideinput. Using multiple taps to identify the nature of a voiding event maybe beneficial because it may prevent device 212 from misconstruing othermotions as characteristic input provided by the patient.

In other example embodiments, a pattern of input events may be used toidentify a voiding event as a controlled or involuntary event. In suchembodiments, a pattern of input events may be defined as the temporalrelationship between more than two input events. For example, a patternmay include three input events. In this case, one example pattern may becharacterized by a short time period between the first and second inputevents and a longer time period between the second and third inputevents. Another example pattern may be characterized by a long timeperiod between the first and second input events and a shorter timeperiod between the second and third input events. A patterned inputevent may also be utilized to differentiate between intentional dataentry, i.e., a patient defined action, and device movement resultingfrom normal patient actions, such as sitting and other patient actionsthat may otherwise be misconstrued as intentional data entry.

Device 212 may operate in an initial learning or calibration mode thattrains patient 10 to enter the patient defined actions. For example, ina clinical setting device 212 may be programmed to enter the learningmode. In the learning mode, device 212 may expect certain patientdefined actions and provide an indication if the patient defined actionswere correctly detected. As an example, patient 10 may enter a specifiedpatient defined action, such as a patterned input event that correspondsto identifying a voiding event as a voluntary event. Upon receiving theinput event, device 212 may provide an audible alert or transmit data toan external monitoring device, such as a patient or clinicianprogrammer, that prompts patient 10 whether the input was receivedcorrectly or incorrectly. Patient 10 may enter the input event severaltimes in order to learn or become accustomed to the temporal andpressure characteristics of the input event that are required for properdetection by device 212. In other words, patient 10 can repeatedly enteran input event until the patient has learned to enter the input eventcorrectly. This training mode may be important for patient 10 to easilyand reliably provide input to identify the nature of voiding events.

In addition, the lack of input may be used to identify the nature of anevent in some example embodiments. For example, a single tap mayindicate that a voiding event was controlled and lack of an input mayindicate the event was involuntary. In other examples, lack of input maybe used to reduce the number of false positives. A false positive occurswhen device 212 falsely detects that a voiding event occurred. In theevent that a voiding event is detected, device 212 may be configured toexpect an input from the patient. The input may be entered within a timeframe following the detection of an event. This time frame may allowsufficient time for the patient to get to a restroom following aninvoluntary event so that the patient may deal with the involuntaryevent and enter input in privacy. However, if the patient does notprovide input within the time frame, then the event is identified as afalse positive.

This may be advantageous because it limits the motions that may bemisconstrued by device 212 as characteristic input. That is, sincedevice 212 expects input a short time period after detecting a voidingevent, other motions that may normally be indistinguishable fromcharacteristic input are not registered because they do not occur duringthe time window of interest. For example, following a detected voidingevent, device 212 may examine the signal generated by the accelerometerover a window of time. This window may be less than approximately fiveseconds, less than approximately 10 seconds, or less than approximatelya minute. In any case, it is unlikely that other motions that could bemisconstrued as a patient input will occur during this time windowthereby further increasing the confidence in the signal generated by theaccelerometer within device 212. In the case that patient 10 is aware ofa an involuntary voiding event, the lack of input may be used toidentify the event as an involuntary event. Alternatively, the event maysimply not be identified as a controlled or involuntary event to avoidconfusion with the case that patient 10 forgot to enter input.

In some embodiments, device 212 may also provide an audible or otherpatient detectable alert as a reminder to the patient to enter input. Asone example, device 212 may provide a beep or other sound that can beheard by patient 10 after a voiding event is detected. This beep mayserve as a reminder to patient 10 to provide input to identify thevoiding event. Alternatively, or in addition to beeping, device 212 mayvibrate in a way that can be detected by the patient. In this manner,device 212 may reduce the likelihood that patient 10 forgets to provideinput to identify the nature of a voiding event and, therefore, mayreduce false positives.

It is recognized that the location at which device 212 is implanted mayhave a significant impact on performance of the device. For example, theperformance of device 212 with respect to detecting a voiding event maybe dependent on the proximity of the implant site to the source of thesound that is used to detect a voiding event. At the same time, theperformance of device 212 with respect to identifying a voiding event asa controlled or involuntary event may be dependent on the on the depthat which device 212 is implanted within subcutaneous tissue 208. Inother words, implanting device 212 in close proximity to the bladder orurinary tract of the patient and shallow in subcutaneous tissue 208,i.e., just under epidermis 206, may increase the accuracy andreliability of device 212 of detecting voiding events and identifyingvoiding events based on input received from the patient.

It should be understood that the embodiment described with respect toFIG. 12 is one of various example embodiments that may be used toidentify the nature of a voiding event based on a patient definedaction. In other example embodiments, the microphone may be used todetect a voiding event and receive input from the patient to identifythe nature of the voiding event. In such an example, tapping skin 212may produce a noise that is detected by the microphone. The soundproduced by the tapping is translated into data by the microphone.Accordingly, a device in accordance with this embodiment may utilize twodifferent signal processing techniques. A first technique may be used todetect a voiding event. This technique may be employed substantiallycontinuously. Upon detecting a voiding event however, a secondprocessing technique may be used. This second processing technique maybe configured to detect the sound produced by tapping skin 212.

Identifying a voiding event as a controlled or involuntary event basedon input received from the patient as described in this disclosure mayprovide certain advantages. One advantage is that the automatic voidingdiary may be more accurate than a written or electronic voiding diary inwhich the patient manually enters data. In particular, device 212 mayinclude features, e.g., alert features, which remind the patient toenter data in response to detecting a voiding event. This may reduce thelikelihood that the patient forgets to enter input and, thus, result ina more complete voiding diary.

In some embodiments, voiding information generated by device 212 may beused to automatically adjust therapy parameters based on the inputreceived from the patient, and in particular, upon detecting aninvoluntary voiding event by associating a voiding event with patientinput indicating the event was involuntary. Device 212 may include atherapy module or may be coupled (wirelessly or via conductors) to atherapy delivery device. In embodiments in which device 212 is coupledto a therapy delivery device, a processor within device 212 may transmita signal to the therapy delivery device indicating a request for atherapy parameter adjustment. Alternatively, the processor within device212 may merely transmit the therapy information to the therapy deliverydevice, which may then process the information to determine whether toadjust therapy and if so, the adjustments to the therapy parameters.Therapy parameters may be adjusted to increase the intensity of therapyin response to detecting an involuntary voiding event. In this way, thetherapy may be increased, for example by increasing stimulation currentamplitude or stimulation voltage amplitude, until the patient no longerexperiences involuntary voiding events or manually adjusts theparameters because the therapy is uncomfortable.

FIG. 13 is a block diagram illustrating various components of device212. In the illustrated example of FIG. 13 device 212 includes sensingcircuitry 220, sensor 222, processor 224, telemetry module 26, memory228, input mechanism 230, clock 232, and power source 234, which aresubstantially similar to sensing circuitry 90, sensor 92, processor 90,telemetry module 96, memory 98, clock 112, and power source 114,respectively, of device 84 of FIG. 5. Thus, device 212 operates in asimilar fashion as automatic voiding diary 84, but includes theadditional features described in FIG. 12.

In general, input mechanism 230 generates an electrical signal inresponse to patient defined input, such as tapping as described in FIG.12. As previously described, input mechanism 230 may be a single ormultiple axis accelerometer located on or within the housing of device212. Processor 224 processes the output of input mechanism 230 togenerate identification information and stores the identificationinformation in memory 228. Processor 224 may also control telemetrycircuitry 226 to wirelessly transmit the identification information, aswell as other voiding information, to an external device, such aspatient and clinician programmer 16 and 18, respectively.

FIG. 14 is a flow diagram illustrating an example technique utilized bydevice 212 for identifying a voiding event as a voluntary or involuntaryevent based on a patient defined action. The flow diagram begins withdevice 212 generating an electrical signal based on a parameterassociated with a voiding event (280). For example, the parameter may bea sound that is associated with voiding events or a physiologicalparameter associated with voiding, such as bladder pressure. In thiscase, device 212 includes a microphone as previously described in thisdisclosure. However, other physiological parameters may also be used todetect voiding events. As an example, device 212 may include pressuresensors, flow sensors, strain gauges, wetness sensors, or other sensorsthat generate electrical signals that can be used to detect voidingevents.

In any case, device 212 processes the electrical signal to detect avoiding event (282). Processing the electrical signal may, for example,involve comparing the electrical signal to a signal template stored inmemory as previously described in this disclosure or comparing anamplitude of the electrical signal to a threshold value. Device 212continues to monitor the electrical signal generated by the microphoneor other sensor when a voiding event is not detected (“NO” branch ofdecision block 284). However, upon detecting a voiding event (“YES”branch of decision block 284), device 212 monitors the output of theaccelerometer to receive a patient defined action (286).

As previously described, device 212 may monitor the output of theaccelerometer for a pre-determined window of time following thedetection of a voiding event. If device 212 has not received a patientdefined action within the window of time (“NO” branch of decision block286), device 212 generates data that identifies the detected voidingevent as a false positive (294). The false positive data may be storedwithin memory (290). In other embodiments, device 212 may generate datathat simply indicates that the patient did not enter input. In any case,the identification data (or “identification information”) is stored inmemory (290) and may be displayed to a user for review (292).

When device 212 receives a patient defined action within the time window(“YES” branch of decision block 286), a processor within device 212 mayassociate the input from the patient via the patient defined action witha voiding event, and generate data that identifies the event as one of avoluntary and an involuntary event based on the received patient definedaction (288). Device 212 may then store the identification data (or“identification information”) in memory (290). The identification datamay be a value, flag, or signal that is stored or transmitted to whethera detected voiding event was controlled (i.e., voluntary) orinvoluntary. In some embodiments, voiding information, including theidentification information or data, is displayed to a user for review(292). In order to display the voiding information to a user, such as apatient or clinician, device 212 may wirelessly transmit the voidinginformation to an external device, such as a patient or clinicianprogrammer, or another computing device. In other embodiments, device212 may merely associate the receipt of the patient input via thepatient-defined action with a voiding event, and the information may betransmitted to another computing device to determine whether the inputindicates the voiding event was voluntary or involuntary.

As previously described, in other embodiments, a patient defined actionconfirming that a detected voiding event was in fact a voiding event maybe obtained through techniques other than device 212. For example, thepatient may provide feedback via a patient programmer or anotherexternal computing device, such as by responding to a prompt from thepatient programmer or depressing a button dedicated to such confirmationinput.

Systems and methods that include a input mechanism that is configured toreceive a patient defined action from a patient in order to determinewhether a voiding event was voluntary or involuntary is described incommonly-assigned U.S. patent application Ser. No. 11/755,587 by MartinT. Gerber et al., entitled, “VOIDING EVENT IDENTIFICATION BASED ONPATIENT INPUT,” and filed on the same date as the present disclosure,the entire content of which is incorporated herein by reference.

FIG. 15A is a schematic diagram illustrating an automatic urinaryvoiding diary system 300. System 300 includes IMD 302 coupled toimplantable medical lead 304. Lead 304 has an elongated body thatextends between a distal end carrying sensor 310 and a proximal endcoupled to IMD 302. In general, IMD 302 is configured to operate as anautomatic voiding diary that detects urinary voiding events based on asensor signal received via lead 304 and records voiding information fordetected urinary voiding events. In some embodiments, IMD 302 may alsobe configured to operate as therapy delivery device, such as anelectrical stimulator, drug pump, or both. In embodiments in which IMD302 delivers therapy to the patient, lead 304 may be configured as acombination lead, i.e., a lead that includes sensor 310 and therapyelement. For example, lead 304 may include both sensor 310 andelectrical stimulation electrodes, or one or more additional leads maybe coupled to IMD 302, e.g., to deliver electrical stimulation, drugtherapy, or both.

Although lead 304 is illustrated in FIG. 15A as carrying a singlesensor, i.e., sensor 310, in other embodiments, lead 304 may carrymultiple sensors. The sensors may include one or more microphones,pressure sensors, flow sensors, strain gauges, sensing electrodes,temperature sensors, any other type of sensor used for generating asignal indicative of a parameter associated with voiding events, or anycombination thereof. Lead 304 may carry two or more different types ofsensors. IMD 302 receives an electrical signal generated by sensor 310(and any other sensors carried by lead 304) and processes the electricalsignal to detect urinary voiding events, and records the voiding eventsin a voiding diary.

In the embodiment shown in FIG. 15A, lead 304 is positioned so that itsdistal end and, more particularly, sensor 310 is proximate to bladder20. However, it should be understood that lead 304 may be implanted atother target sensing sites suitable for sensing physiological parametersassociated with urinary voiding events. Accordingly, the location oflead 304 within patient 10 may depend on the type of sensor 310.

IMD 302 processes the electrical signal generated by sensor 310 todetect voiding events. In particular, IMD 302 may operate as previouslydescribed in this disclosure. For example, sensor 310 may be viewed asthe microphone that generates an electrical signal based on soundsassociated with voiding events. Accordingly, IMD 302 may process thesensor signal to detect voiding events using the previously describedsignal processing techniques, such as filtering techniques for removingunwanted signal components, correlation or comparison techniques thatutilize a signal template, and low power techniques that combine a sleepor low power state and one of the previously described techniques fordetecting voiding events.

System 300 may be particularly advantageous in embodiments in whichsystem 300 is configured to deliver therapy to patient 10 to treaturinary incontinence. Delivering electrical stimulation to the S3 sacralnerve may help treat urinary incontinence. In such embodiments, lead 304may be configured to also deliver electrical stimulation, drug therapy,or both, at target stimulation site 318 proximate to the S3 sacralnerve. Lead 304 may include one or more stimulation electrodes (notshown) or have one or more openings (not shown) for delivering drugtherapy. The stimulation electrodes and/or openings for delivering drugtherapy may be located on lead 304 such that when 304 is fully implantedin patient 10 as shown in FIG. 15A, sensor 310 is positioned proximateto bladder 20 and the stimulation electrodes and/or openings areproximate to target stimulation site 318. In this case, the traumaexperienced by the patient during implantation of system 300 is reducedbecause only a single lead is required to be implanted to achieve bothsensing of voiding events and therapy delivery to treat incontinence.

In embodiments in which lead 304 only carries sensor 310 and a separatelead is used to deliver therapy, certain advantages may still beachieved. In particular, because lead 304 carries sensor 310 proximateto its distal end, lead 304 may be implanted without requiring anadditional incision. For example, the lead or leads that deliver therapymay be implanted within patient 10 through an incision and positioned ata target stimulation site, such as target stimulation site 318 proximateto the S3 sacral nerve. When the therapy leads have been implanted, lead304 may be implanted through the same incision and positioned at adifferent target site. That is, lead 304 is introduced into the S3sacral foramen 312 of sacrum 314 in the same way that the therapy leadsare introduced. However, lead 304 may be advanced towards bladder 20 andpositioned so that sensor 310 is proximate to bladder 20 as shown inFIG. 15A. Thus, no additional incisions are required and the traumaexperienced by patient 10 is reduced.

As shown in FIG. 15A, system 300 also may include a clinician programmer18 and a patient programmer 16. Clinician and patient programmers 18 and16 may be handheld computing devices that enable a clinician and patient10, respectively, to view voiding information and control delivery oftherapy. For example, using clinician programmer 18, the clinician mayspecify electrical stimulation or drug therapy parameters.

Clinician programmer 18 supports telemetry (e.g., radio frequencytelemetry) with IMD 302 to upload electrical stimulation parameters and,optionally, download operational or physiological data stored byelectrical stimulator 12. In this manner, the clinician may periodicallyinterrogate IMD 302 to evaluate efficacy and, if necessary, modify thestimulation parameters. Patient 10 may use patient programmer 16 tostart, stop or adjust therapy. In particular, patient programmer 16 maypermit patient 10 to adjust stimulation parameters such as duration,amplitude, pulse width and pulse rate, within an adjustment rangespecified by the clinician via clinician programmer 18, or select from alibrary of stored stimulation therapy programs. Patient and clinicianprogrammers 16 and 18 communicate via cables or a wirelesscommunication, as shown in FIG. 15A. For example, clinician programmer18 and patient programmer 16 may communicate with each other and IMD 302using any of a variety of local wireless communication techniques, suchas RF communication according to the 802.11 or Bluetooth specificationsets, infrared communication, e.g., according to the IrDA standard, orother standard or proprietary telemetry protocols.

In FIG. 15B, system 300 is configured to operate as a fecal voidingdiary system in which lead 304 is positioned to proximate to intestines330. Positioning lead 304 and, more particularly, sensor 310 proximateto intestines 330 instead of bladder 20 enables lead 304 to be used fordetecting fecal voiding events instead of urinary voiding events. Thus,system 300 in FIG. 15B operates as described with respect to FIG. 15A.

The purpose of FIG. 15B is to describe the unique features of detectingfecal voiding events. These unique features relate to the positioning oflead 304 and the type of sensor used for sensor 310. Sensor 310 may be amicrophone, strain gauge, electromyography (EMG) sensor, accelerometer,piezoelectric sensor, or other sensor that generates an electricalsignal based on a sound, pressure, motion, or turbulence caused by themovement of fecal matter in the intestines, rectum, or bowel during avoiding event. Lead 304 may be positioned, for example, such that sensor310 is located proximate to a portion of the bowel, large intestines,proximate to the sacrum (e.g., below the sacrum), anus, rectum,descending colon, or sigmoid colon.

As an example, lead 304 may be implanted so that sensor 310 is implantedproximate to a portion of the sigmoid colon as shown in FIG. 15B. InFIG. 15B, rectum 336, sigmoid colon 332, and descending colon 338 areshown. Specifically, sigmoid colon 332 and rectum 336 are depicted suchthat their positions relative to one another form a “valve” or “fold”that prevents fecal matter from entering rectum 336. During a fecalvoiding event, however, sigmoid colon 332 and rectum 336 may shift fromthe illustrated positions to positions that open the valve or foldthereby allowing fecal matter in sigmoid colon 332 to pass to rectum 336and exit anus 334. In the illustrated example of FIG. 15B, sensor 310generates an electrical signal based on the motion of sigmoid colon 332and rectum 336 relative to the bulk of patient 10. In this case, sensor310 may comprise one or more strain gauges or accelerometers disposedalong a distal portion of lead 304.

It should be understood that although FIGS. 15A and 15B depict a singlelead, more than one lead may be used to detect urinary and fecal voidingevents, respectively. Rather, the purpose of FIGS. 15A and 15B are toillustrate one example embodiment of the invention and should not beconsidered limiting of the invention as broadly described in thisdisclosure.

FIG. 16 is a detailed perspective view illustrating an embodiment oflead 304, which includes lead body 340 extending between proximal end342 and distal end 344, sensor 310 positioned proximate to distal end344, fixation elements 346A-D (collectively referred to as “fixationelements 346”), and stimulation electrodes 348A-D (collectively referredto as “stimulation electrodes 348”). Stimulation electrodes 348 areelectrically coupled to a therapy module within IMD 302 via conductorsdisposed within lead 304. In particular, lead 304 may include a set ofproximal electrical contacts at proximal end 342 which couple to IMD 302directly or indirectly via a lead extension. In some embodiments,electrodes 348 are coupled to separate conductors, which allows separatestimulation signals to be delivered to each electrode 348. In otherembodiments, two or more electrodes 348 may be coupled to a commonconductor.

Lead 304 is illustrated in FIG. 16 with a single sensor 310. However, inother embodiments, more than one sensor maybe located proximate todistal end 344 of lead 304. As previously described with respect to FIG.15A, sensor 310 may be any sensor that generates an electrical signalbased on a parameter associated with a voiding event, such as amicrophone, a pressure sensor, a flow sensor, a strain gauge, and thelike.

In FIG. 16, electrodes 348 are positioned adjacent to sensor 310 atdistal end 344, but may generally be located anywhere along lead body340. Positioning electrodes 348 proximate to sensor 310 may beadvantageous when the target stimulation and sensing site are in closeproximity to each other. In other embodiments in which targetstimulation and sensing site are in close proximity to each other,sensor 310 may be located between one or more of electrodes 348.Alternatively, in embodiments that have multiple sensors located atdistal end 344, electrodes 348 and the sensors may be interspersed witheach. For example, electrodes 348 and the sensors may be arranged in analternating fashion.

In other embodiments, electrodes 348 may be disposed on a mediallylocated portion of lead body 340 between distal end 344 and proximal end342, rather than proximate to distal end 344 of lead 304. This may beadvantageous when lead 304 is implanted such that sensor 310 is locatedproximate to a target sensing site, such as the bladder or intestines ofthe patient, and electrodes are located proximate to a remotely locatedtarget stimulation site relative to the target sensing site, such as theS3 sacral nerve. In additional embodiments, electrodes 348 may bedisposed proximate to proximal end 342 of lead body 340.

Fixation elements 346 may help fix lead 304 to surrounding tissue andminimize migration of sensor 310 and electrodes 348 from theirrespective target sensing and stimulation sites. Fixation elements 346may be located adjacent to both sensor 310 and electrodes 348 or,alternatively, fixation elements 346 may only be located proximate toone of sensor 310 and electrodes 348. In embodiments in which sensor 310is located at distal end 344 and electrodes 348 are located at adifferent position along lead body 340, fixation elements may preferablybe located adjacent to both sensor 310 and electrodes 348. Moreover, itmay be advantageous for fixation elements to be located both proximallyand distally relative to sensor 310 and electrodes 348. In this manner,fixation elements 346 may prevent sensor 310 and electrodes frommigrating and, therefore, prevent a degradation in the performance oflead 304.

Fixation elements 346 may be, for example, tines, barbs, hooks, and soforth. Alternatively, lead 304 may be sutured to surrounding tissue inorder to secure the position of sensor 310 and electrodes 348. Suturing,however, is typically more invasive then fixation elements 346. In somecases, fixation elements 346 or suturing lead 304 to surrounding tissuemay not be beneficial at all implantation sites. Therefore, it should beunderstood that fixation elements 346 depicted in FIG. 16 are merelyexemplary and the number and location of fixation elements 346 may bechanged based on the implant site of lead 304.

FIG. 17 is a block diagram illustrating various components of IMD 302and lead 304 of system 300. IMD 302 is an implantable automatic voidingdiary that includes lead 304 with a sensor 310 disposed at distal end344. As shown in FIG. 17, IMD 302 includes sensing circuitry 352,processor 354, telemetry module 356, memory 358, and therapy deliverymodule 360. IMD 302 is substantially similar to IMD 12, which is shownand described with respect to FIG. 2. Thus, the description of sensor42, sensing circuitry 40, telemetry module 46, and therapy deliverymodule 32 are substantially applicable to a description of sensor 310,sensing circuitry 352, telemetry module 356, and therapy delivery module360, respectively. Similarly, processor 354 and memory 358 of IMD 302are substantially similar to processor 44 and memory 46, respectively,of IMD 12.

FIG. 18 is a flow diagram illustrating an embodiment of a technique forimplanting IMD 302 and lead 304 including a distal sensor 310 andstimulation electrodes 348 in the body of patient 10. In particular, thetechnique may be used to implant lead 304 by introducing lead 304through a foramen of the sacrum. A clinician may make an incision in theabdomen (370) or other suitable area of the patient, such as the lowerback or buttocks, where the incision is sized to receive IMD 302. Next,the clinician implants IMD 302 in a subcutaneous pocket (372) throughthe incision. The clinician may form the subcutaneous pocket in anyregion of patient 10, such as the abdomen. The location of the incision(370) may depend upon the desired implant site for IMD 302. Accordingly,in other embodiments, the incision and subcutaneous pocket may be madein other regions, such as the lower back of patient 10.

Upon implanting IMD 302, the clinician makes another incision near thesacrum (374) and inserts lead 304, as well as any additional leads,through this incision (376). Next, the clinician positions the leads(378), i.e., lead 304 and any additional leads, by introducing the leadsthrough a foramen of the sacrum and guiding lead 304 to targetstimulation site 318 (FIGS. 15A-B). As an example, the clinician mayposition lead 304 through sacral foramen 312 in sacrum 314 in order toreach target stimulation site 318 and the target sensing site, as shownin FIGS. 15A and 15B. The clinician may fine-tune the position of lead304, such that sensor 310 is proximate to a portion of bladder 20 forsensing urinary voiding events or a portion of the intestines 330 forsensing fecal voiding events. In embodiments in which lead 304 alsocarries stimulation electrodes, the stimulation electrodes may bepositioned proximate to target stimulation site 318, e.g., the S3 sacralnerve. In embodiments in which the clinician implants multiple leadswithin patient 10, the clinician may insert and position each of theleads separately. In some embodiments, the multiple leads may beinserted through a single incision thereby minimizing the traumaexperienced by the patient.

After properly positioning lead 304 or multiple leads within patient 10(378), the clinician may tunnel a proximal end 342 of lead 304 to IMD302, and couple the proximal end 342 to IMD 302 (380). The clinician maythen activate IMD 302 and proceed to monitor the condition of thepatient via an external programmer and begin delivering or testingtherapy as needed.

Various embodiments of the invention have been described. These andother embodiments are within the scope of the following claims.

1. A system comprising: a medical lead comprising: a lead body extendingbetween a proximal end configured to be coupled to a medical device anda distal end, a sensor coupled to the lead body between the proximal endand the distal end, wherein the sensor is configured to generate anelectrical signal that varies as a function of a parameter associatedwith a voiding event of a patient, wherein the voiding event comprisesat least one of a urinary voiding event or a fecal voiding event, and astimulation electrode coupled to the lead body between the proximal endand the distal end; and a voiding monitor that receives the electricalsignal from the sensor and generates voiding information based on theelectrical signal.
 2. The system of claim 1, further comprising a memoryto store the voiding information.
 3. The system of claim 2, furthercomprising a medical device programmer, wherein the medical deviceprogrammer contains the memory.
 4. The system of claim 1, wherein thesensor comprises at least one of an impedance sensor, a strain gauge, amicrophone, a thermometer or a flow sensor.
 5. The system of claim 1,wherein the voiding monitor processes the electrical signals to detectthe voiding event and generates voiding information in response todetecting the voiding event.
 6. The system of claim 5, wherein thevoiding information comprises at least one of an indication of anoccurrence of the voiding event, a portion of the electrical signalassociated with the voiding event or a time of the voiding event.
 7. Thesystem of claim 1, further comprising an external programmer thatincludes a user interface for displaying the voiding information,wherein the voiding monitor includes a wireless telemetry moduleconfigured to transmit the voiding information to the externalprogrammer.
 8. The system of claim 1, further comprising an electricalstimulator coupled to the medical lead, wherein the electricalstimulator is configured to deliver electrical stimulation therapy tothe patient via the stimulation electrode to control incontinence. 9.The system of claim 1, wherein the sensor is coupled to the lead bodyproximate to the distal end of the lead body.
 10. The system of claim 1,wherein the sensor comprises at least one of a pressure sensor or anelectromyography (EMG) sensor.
 11. The system of claim 1, wherein theparameter comprises at least one of nerve activity, bladder volume,bladder pressure, bladder impedance, sphincter pressure, bowel pressure,motion of a portion of an intestines, motion of a sigmoid colon, motionof a rectum or a sound associated with the voiding event.
 12. The systemof claim 11, wherein the parameter comprises a sound associated with thevoiding event.
 13. The system of claim 1, wherein the stimulationelectrode is disposed on the lead body proximate to the sensor.
 14. Thesystem of claim 1, wherein the lead body includes a medially locatedportion positioned between the distal end and the proximal end, whereinthe stimulation electrode is positioned on the medially located portionof the lead body.
 15. The system of claim 1, wherein the sensorcomprises a first sensor, the medical lead further comprising a secondsensor coupled to the lead body proximate to the distal end of the leadbody, the first sensor and the second sensor each being configured togenerate the electrical signal that varies as a function of theparameter.
 16. The system of claim 1, wherein the sensor comprises afirst sensor, the electrical signal comprises a first electrical signal,and the parameter comprises a first parameter, the medical lead furthercomprising a second sensor coupled to the lead body proximate to thedistal end of the lead body, wherein the second sensor is configured togenerate a second electrical signal that varies as a function of asecond parameter associated with the voiding event.
 17. The system ofclaim 1, further comprising the medical device, wherein the medicaldevice comprises the voiding monitor.
 18. A method comprising:receiving, with a voiding monitor, an electrical signal from a sensorcarried by a medical lead implanted in a patient, wherein the electricalsignal varies as a function of a parameter associated with a voidingevent of a patient, wherein the voiding event comprises at least one ofa urinary voiding event or a fecal voiding event, the medical leadfurther comprising: a lead body extending between a proximal endconfigured to be coupled to a medical device and a distal end, whereinthe sensor is coupled to the lead body between the proximal end and thedistal end, and a stimulation electrode coupled to the lead body betweenthe proximal end and the distal end; and generating, with the voidingmonitor, voiding information based on the electrical signal.
 19. Themethod of claim 18, further comprising storing the voiding informationin a memory of a device.
 20. The method of claim 19, wherein the devicecomprises a medical device programmer, and storing the voidinginformation in a memory of the device comprises transmitting the voidinginformation to the medical device programmer via wireless telemetry. 21.The method of claim 18, wherein the parameter comprises at least one ofnerve activity, bladder volume, bladder pressure, bladder impedance,sphincter pressure, bowel pressure, motion of a portion of anintestines, motion of a sigmoid colon, motion of a rectum or a soundassociated with the voiding event.
 22. The method of claim 18, whereinthe sensor comprises at least one of an impedance sensor, a pressuresensor, a strain gauge, a microphone, a thermometer, an electromyography(EMG) sensor, or a flow sensor.
 23. The method of claim 18, furthercomprising determining whether the voiding event occurred based on theelectrical signal, and wherein generating voiding information comprisesgenerating voiding information upon determining that the voiding eventoccurred.
 24. The method of claim 23, wherein determining whether thevoiding event occurred based on the electrical signal comprises at leastone of comparing a characteristic of the electrical signal to athreshold value or comparing a sample of the electrical signal to asignal template.
 25. The method of claim 24, wherein the characteristicof the electrical signal comprises a first power of one or morefrequency components of the electrical signal, a second power associatedwith a portion of the electrical signal or an amplitude of theelectrical signal.
 26. The method of claim 23, further comprisingdelivering electrical pulses to the patient via the stimulationelectrodes upon determining that the voiding event occurred.
 27. Amethod comprising: implanting a medical lead in a patient, the medicallead comprising: a lead body extending between a proximal end configuredto be coupled to a medical device and a distal end, a stimulationelectrode coupled to the lead body between the proximal end and thedistal end, and a sensor configured to generate an electrical signalthat varies as a function of a parameter associated with a voiding eventof the patient, the voiding event comprising at least one of a urinaryvoiding event or a fecal voiding event, wherein the sensor is coupled tothe lead body between the proximal end and the distal end; and couplingthe medical lead to a voiding monitor that receives the electricalsignal from the sensor and generates voiding information based on theelectrical signal.
 28. The method of claim 27, wherein implanting themedical lead in the patient comprises implanting the medical leadproximate to one of a bladder, a urinary tract, a sacrum, an intestineor a rectum of the patient.